Comment 3 for bug 797225

Actually, it seems that Banshee still does not use GTK3, whereas Rhythmbox does. So, I think that Rhythmbox is a better choice than Banshee.
Also, in Oneiric, LightDM is replacing GDM and Thunderbird is replacing Evolution.

This means that UGR will really have to choose between being Ubuntu with GNOME Shell by default but Ubuntu applicactions (Firefox, Thunderbird, LightDM, Banshee...) or being Ubuntu with the complete GNOME3 (GNOME shell, Epiphany, Evolution, GDM, Rhythmbox...).

IMHO, UGR should stick to GNOME3 / GTK3 apps as much as possible. The only exception I can think of is LibreOffice VS GNOME Office because GNOME Office still lacks vital components that LibreOffice provides (presentation tool mainly).