Andy, that part is certainly in the ballpark. I'm also thinking of some Luminary Micro (or other small ARM) parts too. I have some tools that I bought for personal use at home to learn ARM, but haven't really had the time to do much. I imagine it's a pretty steep learning curve. I had another look at AVR and I'm not sold on that architecture yet.

Regarding some of the earlier posts, my idea of what an ICE needs to do are:
- control execution (code breakpoints, single-step, etc)
- memory and register inspection, preferably with a watch window for the vars.
- OK to use a couple of CPU pins, but not internal peripherals. I need my serial interfaces.

Also it occurs to me that I'm kind of drifting off-topic here into the realm of "what should my next micro be", rather than how to update my existing 8051 tool chain.