Photoshop touch actually does work on the Nexus but it's blocked in the Play Store because of the screen size. I took the apk off of my Transformer and loaded it on my N7 and it works really well. I dunno how to get it though (legally) if you didn't buy it on a 10" tab already.
Maybe changing the screen dpi to make it the same as a 10" tab would work ... hmm
Oh right, thanks for the heads up on it....I'll have a sniff about.