Now Konami could go off and make another cheap, mishmash full of recycled ideas and recycled graphics --or they could get serious about developing an ambitious 2-D game to its fullest creative and technical potential. Dracula X Chronicles was a big step in the right direction, but it was a remake and it certainly wasn't developed for the most ideal system to reach the Castlevania fanbase...
Now this is where I see the biggest problem with 2D Castlevanias.
Development of the high quality 2D game will take, most likely, as much money nowadays as development of the 3D title. I don't think that Konami honestly believes in 2D future of the series, especially given Harmony of Despair treatment, that by the end was filled wth lazy copypaste from 8bit games (!!).
If there will be a new fresh 2D title in the series, it probably will be a downloadable relatively short game. And I doubt that is exactly what OA strives to.
In other words - Konami want to make money and they'll do what is considered popular nowadays. 2D games are a mostly a niche market for netwroks and portable consoles and I doubt that Konami will consider a really big 2D title for the PS3 / Box360. Or even if they do, it will not be a Castlevania.
It's very simple. When Castlevania is back in the news, the wayward fans will start coming home. They'll visit Castlevania websites. They'll commune on Castlevania forums. They'll read Castlevania news. They'll search Google, Facebook, and Youtube for all things Castlevania...
And they'll see group of old-school fans who demand Castlevania to be made by standards of 1997. [sarcasm]Sure it would rise the popularity of the project.[/sarcasm]
In reality it will may attract certain people (read: old school fans, who disatisfied with changes for whatever reason), but I doubt it will get major coverage in gaming press and all that jazz. Most likely OA would be seen as another attempt of antique fanboys to turn time backwards.