Imo, the problem with Sony's handheld division is that the PSP initially took off because of the novelty of it being the first handheld PS console, at first, yeah, it worked, but then there came a point where all Sony did was force games with PS3 credentials onto it just as a trojan horse to buy a PSP.. (hey guise, you wanna play the latest God of War, Resistance or Motorstorm games? Want some extra content for you favorite PS2/PS3 games? Screw DLC, you gotta buy tha PSP!)
And that mentality has in turn hurt the Vita, because the novelty has since worn off, the masses realize they're better off just sticking with home consoles for their PS fix and that Sony from a business standpoint view the Vita as just another console, not a handheld.
The sooner Sony go back to their vision of a straightforward line of media-influenced home consoles, and stop trying to expand the "Playstation" name into an all out brand (seriously, "Go", "Xperia", "Vita", how much more cliche can you get? Nobody gives a flying fuck about Vita being fancy Latin for life), the better. I'm not here to say the PSP or the Vita sucks, but their marketing ideology for them is heavily flawed and it's gradually taking away from what got them so thoroughly revered and recognized in the gaming industry to start with.