Let's hope that Matt Aslett won't mind us borrowing this valuable quote from his scoop.

Radcliffe [general counsel, pro bono, for the Open Source Initiative] concludes:

“I believe that the GPLv3 is a very valuable addition to FOSS licenses and solves many of the challenges faced by GPLv2. Companies distributing FOSS should consider it and companies using FOSS should be prepared, in most cases, to accept it.”

There are some wishful-thinking claims that GPLv3 adoption is slow, but these claims are increasingly being dismissed. Some GNU software is not GPLv3-licensed yet, but the move is inevitable. It's a classic example of preparation. Intent to upgrade includes over 5,000 projects so far. The change cannot be applied and completed overnight though.