Yeah, I agree that SotN was a natural progression in many ways. I also feel that Lords of Shadow is a natural progression of what we currently have for 3D titles. Maybe not exactly a natural progression of 2D Castlevanias to 3D, but it does seem like a natural progression starting from 64 -> LoI -> CoD -> LoS. I think part of the problem may be that the 64 title was not really a natural progression from Symphony, and that in itself spurred its own branch so to speak.
The way I see it, it's not that I'm looking for a "rehash" of the "spurred" 64 design, so much as I want to see that design take its natural course of evolution and show us what a more natural 3D Castlevania progression would be when taken to its limit. I wanted that N64 formula perfected visually, technically, and control-wise, before I see the series drastically split off again. For instance, theoretically, if the series had gone from Simon's Quest to SotN, the original NES CV1 formula would have maybe never reached its more complete and beautiful forms in games like Super Castlevania IV.
(The split we're seeing now as far as a re-imagining is kind of like Capcom's Ghosts 'n' Goblins and Maximo, though maybe more so?)
I think the last few posts by Uzo and Shelverton have reached a nice middle ground of understanding of where the problems are in all this. Basically, Castlevania is faced with a need to become more popular, and it's easier/safer for Konami to go with a more mainstream, proven formula than something that might be fine in its own right, but misunderstood by the gaming world. On the flip side, if it did do something of its own as the bulk of the game design, it might become the unique front-runner it used to be in the action-platforming-adventure genre. A sort of nice antithesis to the God of Wars and Devil May Crys. But that give-and-take in design (and art direction) is where the frustration is. (Regarding that art direction, there are splashes of CV, but I can't say IMO how much yet from what we've seen, and the larger divergences have left me uncertain).
Going back, I actually see a break between the N64 games and LoI, though I agree about the progression of LoI to LoS from looking at the popular genres of the time. The sad thing is that they didn't even stay consistent between LoI and CoD. It keeps switching its inspiration point, and both LoI and CoD were never refined in future games (LoI having more potential than CoD, IMO). It kept getting further away from the core of 3D Castlevania. LoS might be a step back in the right direction, but it's not the "revelatory, iconic leap" I want by this point after all the missteps and all the GBA/DS clones that got almost progressively watered down.
As for SotN, I agree that it took A LOT from Metroid...but it seemed to carry the essence of more of a Simon's Quest, which made it make sense for me as a one-off. As that style went on, though, I felt it diverged too far from the strengths of Castlevania. It was a shell of Castlevania, essentially.
I can see this relating to what happened to Ninja Gaiden on XBOX, as Shelverton noted. That wasn't the worst result, but I did miss the platforming and some of the artistic cues from the original Ninja Gaiden series. I have to say, I've never played Prince of Persia, despite seeing it a lot over the years. I know it has beam-balancing and pole-swinging, but I don't know how all the platforming mechanics work, so I'm not sure how that will translate into LoS.
One last thing (issue) in my rambling here: The story of LoS seems a bit too reminiscent of other stories and feels like it is being sandwiched into Castlevania. It reminds me of Shadow of the Colossus, where you slay "Villain X" to get power to bring your love back to life, but said power curses you with darkness. Moreover, the whole pieces of the runic mask remind me of the Fused Shadows from Zelda: Twilight Princess, which eventually turned into a mask with "immense power" when whole.