These boards have been posted about earlier (there was a thread somewhere on here) - its nice to see that you can download the IDE now (though I am wondering if the Linux version will run on 64-bit Linux).
The thing that bothers me is whether by having this higher performance (and lower cost) option, if people will go for it, rather than the standard 8-bit version - in order to simply throw more hardware at a problem which could be better solved with another design. I mean, right now (well, maybe "before") you didn't have much of an option, except for the Mega (or Sanguino) - the lower power forced you to come up with unique and innovative solutions to certain issues. I just wonder if we might see a "code bloat" or "hardware bloat" that is just there to cover for sloppy design (both software and hardware).
Don't get me wrong - more powerful hardware might and probably will lead to even more interesting things coming out for the Arduino; I just don't think the full capabilities of the current "low-end" ATMega328 have been fully exploited.
My only other "gripe" is that the Pic32 doesn't come in DIP form (can't expect it too, either). While nothing beyond the 644 does either, at least that is still an option available (though most people probably don't do standalone designs - so maybe it won't matter for most)...