Yet another Origin fail. I bought it through Origin, after wavering on the fence and not pre-ordering BF3.
The Browser interface says I have Karkand enabled, yet I cannot join any games... luckily I googled before I raged, EA Forums and most other places are full of complaints about this shoddy system.
Also luckily, the fix is easy, if really, really indicative of poor implementation.
Non-Preorder + Bought Back to Karkand in Origin -> Log OUT in browser, then log back in.