The EGit and JGit Eclipse projects released 0.8.1 of their namesake projects earlier this week, in preparation for the Eclipse Helios simultaneous release due later this month. The New and Noteworthy for both EGit and JGit have been brought up to date, and a User Guide based on contributions from the Eclipse Wiki. There's also an Introduction to Git for those who haven't used it before.
As a technology preview, the EGit project is not at full feature-parity of the command-line git tool. Although key features like creating and committing to local repositories (as well as pulling from and pushing to remote repositories) are available, the ability to perform full merges, resolve merge conflicts, and ignore resources are not yet available. (JGit 0.8 does allow for fast forward and already up-to-date merges; but these are only applicable in a subset of cases.)
Since the on-disk format for Git repositories is standardised, EGit can be used in conjunction with the command-line tool. For those that are already command-line git users, the ability to perform some operations into EGit will make a number of day-to-day operations easier. However, those spoilt by the polish of the Eclipse CVS client will find that EGit is still catching up.
The Eclipse Foundation has also recently enabled Smart HTTP on the Eclipse Git servers, which is natively supported by EGit and others like GitHub. Smart HTTP support allows HTTP checkouts, previously written off by Google as slow, to perform at the same speed as the native git: protocol. This brings the time down to checkout a project by an order of magnitude: cloning http://git.eclipse.org/gitroot/mpc/org.eclipse.epp.mpc.git using the Dumb HTTP protocol takes over a minute in total; cloning the same project using the Smart HTTP protocol takes a little over 10 seconds.
There is a frequent release plan scheduled after the Helios release; a 0.9 is planned for September 2010, which should bring full merge and ignore support. As the tooling improves, the expectation is that projects will start to move off CVS and onto Git on the Eclipse infrastructure.
More information can be found from the EGit project page and the JGit project page, or use the update site to install it directly into Eclipse. Please send feedback by filing bug reports against EGit and/or the egit-dev mailing list.