I think it might be a little different this time. I remember when they "open sourced" code in the past they used some freaky restrictive license of their own that nobody wanted to touch[1]. Now they appear to be using accepted open source licenses like MIT and Apache.

I agree with apalmer and worry that as soon as they get some leverage over you, you are still in trouble. I can't predict the future, but I've found past behavior to be one of the best predictors, for better or worse.

1. http://en.wikipedia.org/wiki/Shared_source