If your reason for getting a tablet is mainly for GPS there will be a TON of lower priced Android tablets hitting the market before summer. Joe just picked up Archos 70 7in tablet for like $220. Of course that doesn't include GPS so a bluetooth receiver is needed (I gave him an old one of mine) - they cost about $35.

The Samsung Galaxy is really nice and it compares well with the ipad but if you want a full featured tablet I would wait for the Ipad2 (summer?) or the Motorola XOOM (March). The Xoom has the new version of Android 3.0 Honeycomb on it that is written just for tablets - unlike the ipad and 2.2 Android tables that are just big smartphone operating systems. Check out this: