Congrats on the X200 Tablet! I love the Thinkpads myself and am close to pulling the trigger on the X200 non tablet version. I've been using Garmin Mobile PC since it was offered and was using Co-Pilot before that.
I recently started using my Sprint Overdrive MiFi as a GPS receiver for my X31 Thinkpad. It works without issue and is very comparable to my Deluo Navstick which I had connected to the USB extension cable for better reception. Connection cable is optional on the MiFi of course, otherwise it works excellent via WiFi comm.
I'm not familiar with Verizon, but on Sprint the utility allows you pull up any searches via GPS results in Google Maps, MapQuest, Microsoft(Bing), Yahoo. There are other shortcut searches such as fuel, lodging, etc.