From what I can tell, the Q and some other phones use 'Assisted GPS' or aGPS. Normally a GPS receiver can process all the satellites' signals to get a position fix. aGPS uses a central server to do some of the work (run by your wireless provider). I'm not sure if this is a hardware limitation imposed by size/battery/etc issues, or what. It could also be a software limitation, either just to trim a few hundred kb off the firmware, or an instance of Verizon/Sprint/etc required crippling.
For the conspiracy theorists, it's a great excuse to charge extra for 'Turn by Turn' directions only available from your wireless provider. Of course, nationwide maps with recordings of odd street names runs several gigabytes, and needs updating frequently- a much easier task on a central server.
I think another possible reason aGPS is used over standalone GPS is simple speed. When you turn on a GPS receiver, it can take up to 15 minutes to receive almanac data to accurately locate itself. It may be possible to keep this on a central server, and take raw signals to get a lock in just a few seconds. If I'm right, that is a huge advantage for GPS-enabled 911 systems.
If Google Earth ever releases a version for the Q, I'll be thrilled.
