Thank you for the replies, and that link was helpful.
I went down to a Best Buy that had a Pioneer head unit with "Made for iPod, "Works with iPhone" and Bluetooth, I asked to try my phone on it. I believe the model number was DEH-6100BT(I could be off). Here is what I found, hopefully this will help others.
First, I paired with Bluetooth, it does have a security code to pair. There are quite a few running electronics at Best Buy waiting to pair with Bluetooth, that this took a while, but it worked fine. It then took quite awhile, 2-3 minutes, as it loaded my phonebook (400+ contacts), but as soon as it was done it was ready to go and I could scroll through my contacts on the stereo. I expect this would be a one-time issue with the phonebook sync time, and future pairings would be quicker(?).
There was no mic hooked up in the store, so I didn't make a call. The stereo comes with a remote with a number pad to make dialing and using functions easier.
I then plugged the iPhone in via USB. It began charging the iPhone and playing immediately. When I checked the iPod app on the iPhone it said accessory in use. All control had been transferred to the stereo.
From what I saw, it looks like a big improvement over last years options, and I'll probably go ahead and purchase one.