As much as i hate to say this but Wii U is gonna reach 10m first just because there is a lot of great line up & exclusive games coming next year. Unless the psvita has upcoming exclusive game and not just some crappy re-release port,i don't see it reaching 10m before Wii U do. But of course this is depend when is Super Smash Bros. and other game gonna come out.
Official MEME Thread : http://gamrconnect.vgchartz.com/thread.php?id=174366&page=1
Rate The User Avatar Above You Thread : http://gamrconnect.vgchartz.com/thread.php?id=174433&page=1#42