It seems you can get involved in testing the upcoming Battlefield 2142 patch and booster pack if you so desire. It looks as through it was announced a few days or so ago but there will probably still be places.

What's different about this is that the testing would seem to be on ranked servers and the stats wont be wiped when the beta ends. The sign up page is on combattesting.com.

Thanks Bluesnews

** Update **
The Battlefield site is also carrying an interview with producer Kristoffer Bergqvist that relates the Northern Strike, topics covered include the new unlocks, new vehicles and the modified conquest game mode that will be introduced with this booster pack.