Anecdotal evidence and everything, but I went to my local Best Buy earlier this week and the Vita section was disappointing. It was on the end of the shelves they put video-game stuff on, and there was a demo unit, a selection of about 5 or 6 different games, memory cards up to 16 GB and one WiFi unit with about three 3G units and some starter kits. I looked around to see if they were selling Vita stuff anywhere else but it seemed like that was it.
Overall, it was pathetically small, even for a system that just launched, but the games and systems seemed to be selling decently as there weren't many of them on shelves. I wanted to ask a clerk about how it was selling but I forgot to. Not really sure what to make of it.