I can verify that the X will lock onto satellites without a network connection, but there is a "quirk" whereby in Airplane mode the GPS is disabled (but the toggle still looks enabled). I'll probably throw together a more detailed description of how to survive outside the Verizon coverage area in a separate post, but here's some evidence courtesy of my BB Tour:
Google Maps will show this in the middle of a highway in southern Taiwan, you'll just have to trust that I rebooted my phone outside range of a wifi connection as part of my test
Lock-on time varied from a few seconds to a few minutes, I don't think even in Taipei I saw as long as 10 minutes, but without network connectivity it's obviously much slower.

Google Maps will show this in the middle of a highway in southern Taiwan, you'll just have to trust that I rebooted my phone outside range of a wifi connection as part of my test
