I can't really hold it against retailers that they're cutting back on support for the Vita; it's sort of an unpopular machine, after all (undeservedly so, but still...). They're there to make money, and their premium display space is reserved for more profitable things.
I'm not exactly happy about it, but it's their prerogative.
"Excuses are like poems... they're for sissies, and no one wants to hear 'em!" - Ron Stilanovich
I drive all over the country, and I see a lot of different Walmart and Gamestop setups. Walmart does seem to have given up on Vita, as I see more and more that do not carry any games, and some that even seem to be discontinuing the Vita and is accessories. Gamestop, however, doesn't seem to be doing that. Maybe you guys just live in particularly bad areas for the Vita, but most Gamestop stores I go to have a pretty strong presence, at least as strong as the PSP had. Considering the Vita hasn't done so well as PSP, that tells me that either Vita had a larger shelf presence than it has earned, or the PSP got less that it deserved. Practically every GS I have been to has had even obscure new games in on release day, like the collectors box for Ys: Memories of Celceta. I had a harder time finding copies of OLDER popular games like P4G. Of course, once I bought a game I had a hard time finding, it would suddenly be at every Gamestop I visited after that. The problem isn't with retail support of the Vita, the problem is with the fairly limited library of games. Most of the games are JRPG/RPG or fighting games. That isn't enough to carry a handheld.