After collecting some feedback, the GNOME Release Team has finally decided on the release date for GNOME 3.0: It will be September 2010.
To take a look again at the GNOME 3 plan that was released in April 2009: Click here.
This may come as a disappointment to those that have been very much looking forward to major improvements on the GNOME desktop, but a six-month set-back won't be too bad if it will lead to a better quality release (especially after judging the initial KDE 4.0 release). Additionally, Canonical for instance was not planning on shipping GNOME 3.0 until Ubuntu 10.10 due to Ubuntu 10.04 being their Long-Term Support release and not wanting to ship a potentially buggy desktop, so many desktop Linux users would not even have encountered the 3.0 release until October of 2010.
New module decisions for GNOME 2.30 were also made of course.
On the Gnome devel-announce-list, Vincent Untz wrote:
A wise decision and I'm sure the Gnome 3 release will be fantastic ones it arrives.GNOME 3.0 will be released in September 2010, and in the meantime, we will release GNOME 2.30 in March 2010, continuing our long-standing tradition of six-months releases. Thanks to the input from the community, we were able to draw a clear picture of where we stand today and where we will be next March. As mentioned in the GNOME 3.0 planning document , the release date for 3.0 was not set in stone: while we're using a strict schedule that allows us to release GNOME every six months, GNOME is above all using quality-based release engineering. That's why our community wants GNOME 3.0 to be fully working for users and why we believe September is more appropriate. Note that this release date for 3.0 doesn't mean that 2.30 will be less stable than usual. On the contrary, this will help us integrate the changes that are ready for 2.30, while leaving the parts that are still rough on the edges outside of GNOME, as used daily by our users, until after 2.30 is out. This will solidify both our 2.30 and 3.0 releases. The idea of doing GNOME 3.0 was first seriously discussed in 2008, before focus areas were defined in 2009, alongside a plan to reach 3.0. Those focus areas include revamping the user experience, streamlining the platform and improving the promotion of GNOME. Compared to GNOME 3.0, GNOME 2.30 will see the iterative improvements and bug fixes that people have now come to expect from our 2.x branch, in addition to some preliminary work needed for GNOME 3.0. The GNOME 3.0 planning document was answered by the community with a tremendous amount of work, with various teams taking the opportunity to set their own goals for 3.0. Such goals range from modernizing part of our stack to proposing new UI models for our desktop: those broad changes show our ambition to always offer the best to developers and users, and this make our path to GNOME 3.0 most exciting! Let's make 2010 a fantastic year for GNOME! Vincent  http://live.gnome.org/ThreePointZero/Plan
If you want to test the developer preview of Gnome-Shell, you can easily install it in Karmic Koala via Synaptic.
Source: Andre Klapper (andre) and phoronix.com