Although the GPL is used for almost three-quarters
of free and open source licenses, the fact that OSI has given so much thought (and for such a long time) to approving the GPL, shows pure bureaucracy and it’s well known that OSI and the Free Software Foundation didn't agree all the time.
The GPLv3 was released at the end of June, on June 29 to be more exact, by the Free Software Foundation. If you are a developer and you're worrying that your programs licensed under the GPLv2 will get you in some kind of trouble, think again. The GPL version 2 will remain a valid license, and there's no problem if your software remains licensed under it.
Another thing the developers should keep in mind: GPLv2 and GPLv3 are incompatible, so there's no legal way to combine code that uses the GPLv2 license with code under the GPLv3 license in a single program. This incompatibility only matters when you want to make from two or more programs a larger program, and there's no problem if programs under both licenses are present on a system. One advantage of the GPLv3 is that of patenting. The patent license of GPLv3 will make sure companies that use the GPL will not exclude some users due to some patents they created.
Linus Torvalds said not too long ago that he wouldn’t move the Linux kernel to GPLv3, because he considers GPLv2 a better choice, but he doesn't think this new version of GPL won't be good for other projects.
Some advantages of the GPLv3, which developers should consider, include (among others) support for BitTorrent, compatibility with the Apache license, better internationalization.
Source: GPLv3 is officially open source - Computer Business Review