According to TabletMonsters, if you tether together your iPad and iPhone using a personal hotspot on the latter, it’ll beam the GPS information over too, and you’ll be able to use GPS apps on your iPad even without its own 3G connection. It only updates around once per minute, but it’s still better than nothing, and kills another reason for picking up a 3G version of the tablet.
I wonder if this works with jailbroken WiFi sharing, too? There are semi-legal alternatives to the personal hotspot, and I’d be eager to know if they transmit the same information or not. Personally, I grabbed this app before it got pulled, which lets me tether for free, but lacking an iPad 2, I have no idea if it would work for GPS or not.