People are still waiting for Verizon Wireless to unlock the aGPS on the HTC Touch Pro, the Samsung Omnia, and the Samsung Saga. Even though the XV6900 (or HTC Vogue) also has an internal aGPS chip, Verizon won't be unlocking that. So, if you want to use the GPS on that device, you'll need to do some adventurous ROM flashing. I'm still lucky to have the XV6800 (or HTC Titan, Sprint Mogul, PPC 6800) that has an internal aGPS that works really well once you load a custom ROM and apply a few tweaks (or apply a few tweaks to the MR1 or MR2 ROM released by Verizon).
It's so handy to have a phone that has an internal aGPS. The safety implications of having a GPS device are also huge. In fact, I'm surprised that Verizon hasn't faced any significant lawsuits from people who may have sustained injury that could have been avoided if the aGPS on their device had not been locked or disabled by Verizon.
Well, fortunately Verizon won't be crippling future smartphones that have a built-in aGPS. However, there are many current customers who are waiting for that software upgrade!