Im all for a Brand split, depending on how it's done! Smackdown needs to matter again and Raw has become very stale over the course of the last few years.
I would suggest Keeping the IC title on Owens and having him exclusive to Smackdown. He's a great talker, very good in ring and has all the attributes to carry Smackdown as a top heel (some would say he's already the best/top heel in the company, and i wouldn't disagree). However that alone wouldn't be enough to draw much/enough interest back to Smackdown, so i would also have Cena exclusive to Smackdown for a while.
Although they've already feuded (Cena/Owens), i don't see why they can't have another programme on Smackdown together. And it could easily work - Cena could cut a promo saying how 'he's won everything in the WWE, but never the IC title' etc....For all Cena's faults, he more than makes up for it with his good in ring ability, talking, main event status and stature in the company. And he also done superb work in making the US Title actually mean something again last year, no reason why he can't do the same with the IC Title. And tbf, Owens has been spared the comedy shite that hampers so many talented heels in the WWE of late, and he himself is doing a good job with the strap.
As for promoting NXT talent, i wouldn't have them exclusive to any brand. Raw still needs to create buzz, and having NXT talent debut on Raw is the logical step imo.
I think the only thing getting in the way of a brand split (the main thing anyway) is 3+ hours of Raw programming every week. They can't make too many wrestlers exclusive to either brand atm as they have too much time to fill on a Monday. And time to be filled with wrestlers who hold little drawing power atm.