In the recent CV interview with Scott Lobdell accompanying the 'leaked' images from Teen Titans #7, Lobdell implied that Raven might not be appearing in Teen Titans and that DC had other things in mind for her; http://www.comicvine.com/teen-titans/65-19081/exclusive-images-from-teen-titans-7-reveal-future-plans/92-655925/#68
CV: And Raven? A few months ago you mentioned she'd be in the books right about now. Can we assume the crossover has delayed her arrival?
SL: Something delayed her, but it wasn't the crossover! It turns out DC has much bigger plans in store for the character and when you hear what they are you'll understand why she's too big for our little book!
As some forum goes have speculated, Raven's may be the missing Daughter of Darkseid he came to Earth for in Justice League. Personally I doubt this, since I don't really see any point behind DC swapping one inter-dimensional monster of a father for another.
But what do you guys and gals think these 'too big for TT' plans are?