You still need to install hamster from sources but this is a big step forward.
Go get it!
https://extensions.gnome.org/extension/425/project-hamster-extension/
After installing reload the page and you will get to prefs too, in case you don’t like hamster right in the middle of the panel or would like to just have the icon.
It’s still work in (slow) progress of course.

nice, nice, nice.
I use the hamster software on daily basis, so I’m very happy to see things working nicely the gnome3 way…
I just installed the extension, but without installing hamster from source.
I’m using hamster-applet (2.91.3+git20120514.b9fec3e1-1) from debian testing, and it seems to work so far.
what will I miss? or is my version OK already?
cheers, Martin
PS: I would be happy to see you posting on Google+, like Debian and Gnome already doing ^^
judging by the timestamp in the version – they are using git master so that’s the same thing.
as for posting to google plus – that means double posting, but sure, here you go: https://plus.google.com/116623945426658314579/posts
Long live the critter!
I waited a long time for this!