Yes...it was a little rough at first, but now that we have CLockwork mod recovery, an update that includes better calibration, AND an update that adds root with SU Permissions, a fix for the /cache issue once you've done the market work around, and a Nexus 1 boot animation as a cherry on top...
It's running rather nicely for me..got ADW Launcher, RotateD( for auto Landscape, Portrait rotation ).
So far the only applications I haven't been able to run are apps that require the accelerometer, and ones that MUST have GPS.
For some reason GLBenchmark will not run at present, but I've reported that already. OpenGL does work because I've used several example test suites that test OpenGL support, and I was surprised by how smooth this little guy ran at 600Mhz.
Mind you, I'm not saying I'm 100% happy with it. Not quite, but is it worth the investment to "test the waters"..definitely...someone already working on optimizing the Dalvik JVM for the TCC8902 ( the GT's processor ), so even w/o Froyo ( which, as I understand it, is being worked on ) this little guy should be reasonably responsive.
As with everything....your mileage may vary.