In its Judgment of 19 December in case C-274/12 P Telefonica v Commission, the CJEU has continued to define (and minimise) the scope of Article 263(4) TFEU and, particularly, the 'new' third limb introduced by the Treaty of Lisbon according to which 'Any natural or legal person may [...] institute proceedings against [...] a regulatory act which is of direct concern to them and does not entail implementing measures.'
The restrictive approach adopted in the interpretation of this provision is largely based on the (substitutive) potential reliance on requests for a preliminary ruling under Article 267 TFEU against the measures not susceptible of a direct challenge by 'non-qualified' applicants. Therefore, the CJEU has now (almost) completed the reinterpretation of the post-Lisbon mechanisms for judicial review, where it seems clear that Article 263(4) TFEU, and particularly its last limb, is bound to have (or continue having) a marginal role.
In Inuit, the CJEU made it clear that legislative measures are not covered by the concept of 'regulatory act'. However, that negative approach to the definition of 'regulatory act' left some questions unanswered (are those only legislative measures derived from the ordinary legislative procedure as the GC had found, or are there all legislative measures, independently from their ultimate legal basis?). It was also not considered what 'implenting measures' meant. This has now been addressed in Telefonica.
The arguments provided by the CJEU are worth reading carefully:
27 As the Advocate General has observed in points 40 and 41 of her Opinion, the concept of a ‘regulatory act which … does not entail implementing measures’, within the meaning of the final limb of the fourth paragraph of Article 263 TFEU, is to be interpreted in the light of that provision’s objective, which, as is clear from its origin, consists in preventing an individual from being obliged to infringe the law in order to have access to a court. Where a regulatory act directly affects the legal situation of a natural or legal person without requiring implementing measures, that person could be denied effective judicial protection if he did not have a direct legal remedy before the European Union judicature for the purpose of challenging the legality of the regulatory act. In the absence of implementing measures, natural or legal persons, although directly concerned by the act in question, would be able to obtain a judicial review of that act only after having infringed its provisions, by pleading that those provisions are unlawful in proceedings initiated against them before the national courts.
28 It should be explained in this regard, first, that where a regulatory act entails implementing measures, judicial review of compliance with the European Union legal order is ensured irrespective of whether those measures are adopted by the European Union or the Member States. Natural or legal persons who are unable, because of the conditions governing admissibility laid down in the fourth paragraph of Article 263 TFEU, to challenge a regulatory act of the European Union directly before the European Union judicature are protected against the application to them of such an act by the ability to challenge the implementing measures which the act entails.
29 Where responsibility for the implementation of such acts lies with the institutions, bodies, offices or agencies of the European Union, natural or legal persons are entitled to bring a direct action before the European Union judicature against the implementing acts under the conditions stated in the fourth paragraph of Article 263 TFEU, and to plead in support of that action, pursuant to Article 277 TFEU, the illegality of the basic act at issue. Where that implementation is a matter for the Member States, those persons may plead the invalidity of the basic act at issue before the national courts and tribunals and cause the latter to request a preliminary ruling from the Court of Justice, pursuant to Article 267 TFEU (Case C-583/11 P Inuit Tapiriit Kanatami and Others v Parliament and Council  ECR I-0000, paragraph 93).
30 Second, as the Advocate General has observed in point 48 of her Opinion, the question whether a regulatory act entails implementing measures should be assessed by reference to the position of the person pleading the right to bring proceedings under the final limb of the fourth paragraph of Article 263 TFEU. It is therefore irrelevant whether the act in question entails implementing measures with regard to other persons.
31 Third, in order to determine whether the measure being challenged entails implementing measures, reference should be made exclusively to the subject-matter of the action and, where an applicant seeks only the partial annulment of an act, it is solely any implementing measures which that part of the act may entail that must, as the case may be, be taken into consideration (C-274/12 P at paras 27 to 31, emphasis added).
The Judgment could be criticised in view of the fact that it includes implementing measures to be adopted by the Member States within the definition of 'regulatory acts...' in Article 263(4) TFEU--which (under a more generous approach) could have been limited to acts that require implementing measures by the European Institutions, but not those that require implementation by the Member States. However, the logic of the Judgment is clear and the strong push to 'redirect' litigation towards Article 267 TFEU is clear and consistent.
It is also clear from the Inuit and Telefonica Judgments that the CJEU is keeping the 'Plaumann test' alive and kicking when it comes to the interpretation of 'direct and individual concern' under the second limb of Article 263(4) TFEU.
Finally, it is also cleat that the CJEU sees no violation of Articles 6 and 13 of the European Convention on Human Rights or Article 47 of the Charter of Fundamental Rights of the EU as a result of its restrictive interpretation of the locus standi criteria in Article 263(4) TFEU (see paras 56 to 61, where the CJEU stresses once again that 'Judicial review of compliance with the European Union legal order is ensured, as can be seen from Article 19(1) TEU, by the Court of Justice and the courts and tribunals of the Member States. To that end, the FEU Treaty has established, by Articles 263 TFEU and 277 TFEU, on the one hand, and Article 267 TFEU, on the other, a complete system of legal remedies and procedures designed to ensure judicial review of the legality of European Union acts, and has entrusted such review to the European Union judicature', at 57).
Bottom line, the CJEU is clearly stressing that domestic courts of the Member States are EU courts for all purposes. In my view, from the perspective of the design and manageability of the system, this is certainly the only sensible and viable strategy.