deb ftp://ftp.debian.org/debian ../project/experimental main
deb-src ftp://ftp.debian.org/debian ../project/experimental main
deb http://pkg-gnome.alioth.debian.org/debian experimental main
deb-src http://pkg-gnome.alioth.debian.org/debian experimental main

Then, insert the entries below into your /etc/apt/preferences (create it if there is none):
Package: *
Pin: release a=experimental
Pin-Priority: 650

Package: *
Pin: release a=unstable
Pin-Priority: 600

Followed by „apt-get update && apt-get -t experimental install libgnome2-0”

NOTE: You may find that Nautilus will install without problems but it won’t run and experience other issues like all desktop icons you may have created in GNOME 2.6 not showing up; changing desktop background not working, etc.

Recompiling Nautilus is the only way out. The suggested solution is as follow:
1.) apt-get -t experimental build-dep nautilus
2.) apt-get -t experimental –build source nautilus
3.) dpkg -i *.deb

Should Step 2. fails i.e. building of the packages fails, you may need to do an „apt-get -t experimental upgrade’ and retry Step 2 and then proceed to Step 3. Btw, Step 2 should give all a pretty decent idea as to what Gentoo is like i.e. source compiling/building optimized packages. Go take 2-3 ciggies + maybe a jog or whatever. By the time you are done with them, the build process may still not be finished and if the build fails, it’ll mean going through the whole process again (i.e. after apt-getting the missing dependencies such as libeel-2 from either Unstable or more likely Experimental) :D. Still fancy doing a complete install this way?;)

But should the packages build and install smoothly, lo and behold what a beauty indeed is GNOME 2.8. FYI, Ubuntu Linux (a Debian-based effort) is the first distro released with GNOME 2.8. Most of the folks behind Ubuntu are the SAME devels and maintainers behind the Debian GNOME project e.g. Jeff Waugh (also with GNOME itself), Jordi Mallach, etc.