Have you guys seen this contest being put on by Renesas? It has nothing in particular to do with Arduino, EXCEPT that Renesas seems to have reached the conclusion that there is some interesting ground to be covered by allowing a microcontroller board and PC-host-side software to talk to each other. Something the Wiring and Arduino folks have been doing for quite a while now, and might allow one of "us" to blow away competition in the contest.
Their web pages seem a bit disjointed, but as near as I can tell what they've actually DONE is equip their standard (USB-based) debug interface with some extra firmware to implement a USB/Serial port, which they then actually connect to the serial pins of the target CPU, using a couple of spare pins. They say they're going to do it on ALL of their development systems. (I guess there might be pc-host-side software to implement a com port driver as well.) It doesn't sound like much, but it's nice to see a vendor implement something like this, as "real" com ports disappear from our PCs. And apparently they noticed the need based on previous contest entries; not too shabby!
So anyway, here's a chance to expand beyond AVR, if you're so inclined. Free development kit (64k Flash, 2k ram) for contest entrants, $5000 cash first prize, No actual hardware needs to be submitted, etc, etc. Based on the development kit, it looks like they're somewhat more caught on the idea of using the PC as a microcontroller peripheral rather than on using the micro as a PC peripheral, but I think there are still a lot of Arduino projects I've seen that would make fine entries with only a "small matter of programming" to port them to the appropriate Renesas CPU. (Renesas is THE largest provider of microcontrollers, selling the former Hitachi and former Mitsubishi product lines. They've never gotten much traction with hobbyists, though...)
Details here (requires some digging): http://contest.renesasinteractive.com/