I've come to terms with a few facts about CV's future, and I don't think we will be able to retread the paths we've already traveled. While I would love to see some collections or anthologies assembled to consolidate the existing titles in a newer format, any new entry past LoS2 will need to move into fresh territory.
1) We can never truly relive classic 2D side-scrolling like CVI-IV, as gaming has simply progressed too far beyond that format.
2) Metroidvania games by Iga were great, but their decreasing popularity and lower profits are part of what led to Western development in the first place. SotN cannot be fully replicated.
3) Love 'em or hate 'em, LoS will be done next year. There won't be much Konami can do to expand it, though a next-gen trilogy release including MoF HD and all LoS1&2 DLC could be nice to incapsulate it.
4) The old timeline is too crowded to add much more to it. If Konami keeps trying to squeeze in chapters, it will likely damage existing classics, and I doubt we will ever see an entry based directly on the 1999 Demon Castle War.
Honestly, I don't trust Konami to do CV internally any more, and I would be fine if another Western studio got a crack at it. WayForward, Chair, and Retro have all been mentioned, and those would be fine if we're talking 2D. But it could also be nice to see CV updated as a customizeable open-world action-RPG, something more frenetic than Dark Souls or Skyrim but possibly in that vein. Frankly, I'll try to be happy with any new CV, no matter what direction it takes. I just want them to continue, and I would prefer for them not to suck.