There needs to be some clarification surrounding the voice/data issue.
You can:
1.) Talk and open your contacts
2.) Talk and read e-mails that you have in your inbox
3.) Talk and browse through the phone, play games that aren't actively transmitting data
4.) Talk and browse the web if you have a Wi-Fi connection. For some this will be many places, the exception being your car (I'd like to see someone browse, talk and drive)
You can't:
1.) Talk and browse the web over 3G.
2.) Talk and play an online game over 3G
In addition:
1.) If you're streaming Pandora/XM/Sirius and a phone call comes in, the call gets priority. Your stream will stop, and the call will ring. Once you hang up the stream will continue.
2.) If you are synching your e-mail, and a call comes in, you will get the call.
3.) If you're playing an online game, you will still get your call.
Calls take priority over data. You won't have calls going to voice mail all day long. You will find this experience to be a non-issue unless you're obsessed with giving friends directions at the same time as you talk with them. That is all.