Going off of their current decisions and directions, and trying to remain positive, I'm going to guess it is a brand new IP (for BioWare at least - as in not something BioWare has worked on before) AND it'll probably be another blending genres game.
They want to hit a larger audience. They want to pull people into RPGs without letting them scoff at RPG "hard core" turn-offs.
What are top sellers? They already have fantasy and sci-fi. They already have actiony combat and shooter. And they are about to release an MMO. What's left that are remarkably good sellers?
Sports.
No other genre is currently top selling on any platform.
I don't see BioWare doing a sports RPG, but I actually might be intrigued.
But what other franchises might be big ENOUGH or on a come back.
Strategy. Adventure.
I'm going to ignore strategy. It's possible, but most of BioWare's games have had some small "strategy game" elements in them, and I doubt they'd shift focus to that alone (not historically their strong suit) - though, like sports, I'd be intrigued.
So, adventure.
I'm thinking of two modern-ish franchises they could look to for inspiration.
Grand Theft Auto (more action than adventure, but still)
Uncharted (action-adventure, sure, but the most successful "adventure-like" game in a long time)
Uncharted, specifically, does many things that are right in BioWare's bailiwick. And I'd strongly argue that it really is the direction that BioWare SHOULD be focusing, as their strength is in story-telling and characters and choices and NOT in gameplay mechanics.
So I'd expect that their best financial decision, one that they could sell to stockholders or investors or higher-ups or whomever, that best plays to their strengths AND YET is different from what they've done before...
is some kind of modern-day setting (maybe near-past or near-future, but real-ish Earth setting) action-adventure RPG hybrid, focusing strongly on cinematics, casting, melding gameplay into story better and providing real choices in story direction and plot results. RPG elements would of course be present in some format, but character creation will most likely be all but gone (which, given where BioWare wants to take games apparently, is fine at this point - lost cause to fight it out) with maybe a choice of a few pre-sets (Jade Empire) or more of a DA2 / ME series take where you alter appearance and (maybe) chose some background traits.
That's my guess. As well as something I think would be successful for them and something I could get behind.
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Other cynical guess would be a Farmville or Angry Birds clone.