Hi,
One of the things that came up in yesterday's chat was about ARM vs Thumb2. If some folks are interested in a high level overview that doesn't go into too many details with respect to the ISA that I know a compiler writer will be interested in you could read this presentation unless you've seen it. At the minute the canonical way of figuring out more about Thumb2 is really to read the ARM-ARM.
https://wiki.ubuntu.com/Specs/M/ARMGeneralArchitectureOverview?action=Attach...
This was a presentation that Dave Rusling gave at the UDS in Belgium last year, it roughly covers the architecture at a high level and talks about Thumb2 vs ARM , why Thumb2 , the evolution of the ARM architecture etc. It's not a lot of detail but quite a high level overview.
HTH
cheers Ramana