He was a software engineer at Google for five years, and not fired for being bad at programming. And lots of people think his firing was unfair. I think he'll be OK.
Sure, some companies will still not like his stance, but they wouldn't have hired him previously either. Some companies that would have passed will probably give him a second look with this to explain his side of the situation.
2. If he wins against Google in court, he might not really have to care about his career.
3. Cashing in on your fifteen minutes can equal money. People will ask him to speak. People will ask him to do exclusive interviews, etc.