I would love to try out the latest gnome-shell from git but it is having difficulty compiling on my machine. Not to mention, it's an extremely time-consuming process with terse error messages, so it's been hours of trial-and-error so far. I even tried it on a natty setup but it didn't work. The one from the repos works great, but it's fairly outdated from what I understand. Are there any charitable devs out there that want to contribute a deb or PPA for those of us who would like to try it out?
There doesn't appear to be a PPA of git snapshots for 10.10, unfortunately. However, it is actually rather simple to build yourself: upstream (gnome-shell developers) have provided an easy-to-follow guide telling you how to do this. You could give that a go.
There's an even easier tutorial on building it here that also gives you solutions for common problems you may encounter.
PPA with testing version of gnome-shell is available, but only for Natty -- https://launchpad.net/~ricotz/+archive/testing
You can try to use it in Maverick (but it probably won't work).