PS Touch is supported on Android 3.0 (Honeycomb) and higher, but it was meant for 10+ inch tablets. I know the Note is as powerful as a tablet, but technically it's not, especially its screen size (a little over 5 inches).
Maybe someday in the future Adobe will expand support to smartphones (both Android and iOS).
That would be great! Galaxy note + photoshop touch = match made in heaven
fyi many have already successfully installed tablet apk on galaxy note without any issues! So why the wait? :p
PS Touch successfully on a smartphone? Sounds like a hack as, to my knowledge, Adobe has not added support.
(Don't install APKs from unofficial sources, kids. Just a PSA.)
ON EDIT: Also need to clarify: an 8.9 inch screen is required, not 10+ as I mentioned before.
I don't see why the screen's physical size is a factor. The resolution of the note is 1280 x 800 which is what most of the first gen honeycomb tablets are using. ICS should have all of the necessary OS componenets and the note is more than capable of handling it with it's resolution. As the OP mentioned there are people already successfully running it on rooted devices where the application has been purchased from the play store rather than sideloaded. It seems pointless to me that the device would be prevented from running when all it likely is is a change in compatability requirements form the play store which would take virtually no work from adobe.
Just to clarify, while the screen is "only" 5.3 inches the resolution meets whatever minimum requirements there are, it also has a stylus which would allow for the use of any buttons that may appear smaller due to the physical size of the device.