When it comes to the future of the Castlevania series, I think Konami is going to continue in the LOS universe. Them going back to the original timeline would be like a step backwards, as most people would not be familiar with what is going on and would become confused quickly. The fact that Konami wanted the ending changed is just proof that they have plans for a Lords of Shadow 3, be it a prequel or a sequel. (assuming LOS2 sells well, of course) Personally, as lackluster as that ending and final battle was, I'd rather them end it here than have 10-15 games in one universe before deciding "Uh-oh, we're running out of spaces in the timeline! Time to reboot!"
If Castlevania is going to not run into the same problems the original series did, the developers need to think of ways to push the series' gameplay forward and not rehash the same basic style of gameplay from seven games prior. Granted, not every problem the original series had was controllable. (games being released back when plots in video games weren't all that strong) Having every game in the series being about the Belmonts would only lead to it getting stagnant in the long run, especially if they all have the same basic abilities and backgrounds. Same thing with Dracula being the last boss of nearly every game in the series. Who said that Dracula had to be the final boss? Why not give a gameplay and story reason for some other monster/malevolent being/whatever to be the last boss, be it Death, Walter Bernhard, Carmilla, Frankenstein, or even a rogue Belmont who is the final boss because <insert whatever well-executed plot point here>?
My point is that, with a title as generic as Castlevania, you could make it about pretty much anything as long as a castle is involved in some way or another.
At the end of the day, though, I am happy with whatever Castlevania game is released as long as it's fun to play. That's part of the reason why I plan on getting LOS2 tomorrow because, as unsatisfying as the ending and final battle is, what matters when I'm playing a game is if I am having fun and not whether the game has any connection to the old timeline. (not that that's a bad thing, though that wouldn't apply to LOS2) Granted, the reviews for the game will sway how soon I will be getting the game, but I still think I will enjoy the game in spite of it's flaws.