They are always balancing, however with the hew beta they are doing 2v2 automatch and 3v3 automatch. As far as I can see that is all they are adding. there are no new units or new maps as far as I can see.
The PE were great, if a little OP, then they were nerfed, then they were on balance as they are at the moment. I really really hope that they sort out the balancing issues in the patch as it is nearly impossible to play as them within the beta.
Seriously my team mate and I got spanked, and I mean really spanked like we were a couple of noobs, in a few games the other week. We were playing aganst a mixture of yank and brit forces. When chatting to the guys on the opposite teams while we were going through our death throws, they all said that they can't win as the PE on the beta, so they play as allies. They all said it!!! Glad it wasn't just us. Hope this has filtered through to Relic.