So after the turmoil of being thrown into a new desktop metaphor, I've finally reached a stage where I'd feel less at home in Gnome 2.3 than 3.0. Truth be told, the new gnome is both pretty and quite responsive. Key to making Gnome 3 usable is, however, that enough shell extensions are installed that it works similar to the old gnome. The application centric desktop may work for casual users (email/browser), but not for traditional linux/unix applications where different parts of a work flow is handled by different applications (e.g. latex -- scripting/composition in one application, compilation by another, inspection in a third; or gnuplot -- data preparation, gnuplot scripting, visualisation of output file).
But once all the shell extensions are installed, it's back to business as usual.
Even Linus seems to be coming around to Gnome 3 after mumbling about defecting to xfce4: https://plus.google.com/102150693225130002912/posts
So far I've only had one unresolved problem - an 'old' desktop with a radeon 5400 hd card won't run gnome-shell on debian testing. No acceleration. Oh well. At least all my other computers are reasonably happy so far.