SourceCurrently there are some features that need to be completed and some bugs that prevent
GIMP 2.8 from being finally released. Martin Nordholts just posted something
about that on the official mailing list. There is also a discussion about spending money for fixing bugs (so-called bounties), which could be a good way to speed things up. However in the past the devs didn’t like the idea of bounties, because it is difficult to determine what bugs are eligible of being bountied, and of course it isn’t so easy to get a good workflow for a bounty-system in place.
Also we took a look into the
current release schedule file that is updated from time to time, which currently says that there are plenty of things to be fixed, but – and thats whats the good thing on it – it also says that GIMP 2.8 could have a release candidate in late Q1 2011. This is an estimation, however.
GIMP currently has only 3 active core developers (Sven Neumann, Michael Natterer and Martin Nordholts). This is also the fact why the development goes pretty slow, since Martin has had less time to work on GIMP than expected. Alexandre Proukadine has written some news about that here:
Libre Graphics World news on GIMP 2.8Please consider a donation to the GIMP team. But what GIMP really needs is pure manpower to get more releases and features, so try to help by getting in touch with the GIMP development itself! At least 16% of our users told us that they would be able to hack on the GIMP core! Now it’s time to prove it! 
We currently see GIMP 2.8 on the horizon of Q1, but a final release will maybe be in Q2 of this year! We’ll keep you up-to-date.