Can a dual SIM Android phone receive voice calls to both SIMs?

Is it possible for a dual SIM phone to receive calls (not simultaneously of course) to both SIMs without any manual switching?

From what I have seen, Android 4.0 seems to support voice call for SIM #1 and video call (which seems to imply voice too) for SIM #2. That seems like you get 2G voice coverage for SIM #1 and 3G voice coverage for SIM #2. Is this true?

I guess this may vary depending on particular phone model, but what solution is Android dual-SIM industry mainstream currently?