If I upgrade to lion, will FCS 2 still work?
As far as I can tell, Final Cut Studio 2 will run on Lion, but will not install on Lion. Apparently, the installer program requires Rosetta, but the software itself does not. So yes, it should work, if it never needs reinstallation, but if it does, you're stuck. Proceed with caution.

Sources:


https://discussions.apple.com/thread/3134652?start=0&amp;tstart=0
personal experimentation