I'm having the exact same problem, and I've tried all of the workarounds EA and others have provided. I've done a clean boot, a flushdns, I'm running Origin and SWBF2 as administrator, I've got exceptions in my firewall for both programs AND I've even tried with my firewall completely disabled, with no change. I've even gone so far as to completely uninstall and reinstall the game, with no effect whatsoever.
I'm also on the Oregon server at 49MS at the moment, but I've tried other locations just to see if that would make any difference, and of course it did not. I know it's not my network; other online games run perfectly fine for me and my download/browsing speeds are lightning fast.
I'm getting REALLY tired of getting dropped out of matches, guys. This cannot be ignored. Please fix this problem, or provide functional workarounds because the ones EA has provided don't change a thing.