I have 2.0, and I just bought Daxter... I know that I could downgrade and play it on 1.5, but I don't really feel like screwing with flash stuff at the moment, and I probably won't even be able to save my game.
I've been trying the different homebrew games as they come along, and nothing has really struck me as worth playing over the UMD games. The homebrew applications are cool and all, but I have a 20GB iRiver device for all my music and videos. The web browser input history and RSS Audio functions are pretty cool, and they'll be enough to replace the homebrew stuff. As for Monkey64 and other such emulators... I've played most of the good N64 games to the point of no return; the last thing I feel like doing is playing through Ocarina of Time and the like AGAIN on my PSP. With Macromedia Flash right around the corner, I doubt I'll miss the homebrew games that I've seen so far.
Much more importantly, if there's any homebrew game that really impresses me, I'll buy a used copy of GTA. I've got no interest in ISO loaders, and I'm not such a big fan of the alternative interfaces.
I realize that this may be discouraging to homebrew developers, but I'm just one person. I know good and well that most people here love homebrew. Ever since the days of WipEout Pure being the best PSP game were over, I've been more than happy with the UMD games. Many people disagree.
Got anything to say before I upgrade?