I'm also reading on XDA how you can use a dongle to get 3G. though I can achieve 3G making a wireless hotspot with my phone. There seems to be few limits with the tablet.
I can't say I'm a fan of Polaris (software). I'll look to see if there are alternatives.
Have you seen anybody successfully using a 3G dongle with the transformer?
Can you please point me to the thread? My searches on xda were unsuccessful :(