A user reported an issue to me earlier today, I'm still trying to get a logcat from the individual but if I can't get one in a timely manner I'll make one myself.
I believe they're still on the initial release, so 1.0.1
The issue is that when you put the phone on speaker for a call, then back to handset, the microphone refuses to re-initialize. You have to reboot the phone to make it work again. As you can imagine this is a pretty big issue. I don't know if this is exclusive to inbound or outbound calls.
I just thought I'd pass that along. If I don't hear back from the user by the end of the day I'll just go ahead and see if I can't reproduce the issue. If this has already been reported in the last day or so my apologies, I'm about 10 pages behind and haven't caught up yet.