yes.
Current alternatives are default, desktop-background and desktop-splash.
yesterday, I have added desktop-grub and submited the related bug:
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=495282
At the moment, desktop-base doesn't interact with usplash/splashy only
(we don't have an official bootsplash used in Debian, I have hope for Lenny+1).