I just learned that v10 is available "over the air" and I successfully installed it on my phone. Folks at the env Touch forum are saying you need v9 on the phone before the upgrade will be offered. No official change-log available AFAICT.
I've been lucky with my enV Touch. In the year and a half that I've had it I've only seen it reboot once or twice. I've also had it turn off but again very rarely, so I didn't really have a problem to solve. Some folks in the env touch forum are saying the web browser is a little faster with the v10 firmware, but I can't say for sure.