The 2011 Macbook Pro uses a Broadcom 4331 chipset for which there exists no driver at this point. And according to the Ubuntu forums NDISwrapper does not work either.
However Broadcom states that:
"We have plans to support the BCM4331, and other new chips, with the
brcmsmac driver. I don't have an ETA, but new chip support is the first
thing on the priority list after getting the brcmsmac driver out of staging."
Also there are also community efforts to create a driver and today one kernel-hacker told me:
"Hey, the work has just started and its really hard as we don't have ANY specs. Everything I write is from dumps without knowing real stuct of the driver. There is a lot if guessing, starring at the dumps and trying to find a relation with specs for older cards.
I'm on vacations right more, I expect to perform first tests in 2-4 weeks, do then ill be able to tell you more."
So all one can do at the moment seems to be buying an wifi-stick (which sucks, since the macbook wifi was four antennas and should provide a really nice connectivity) or wait.