I've played around with it in recent times and I'd say it's a wonderful application (2.37 was felt a bit nicer to work with than the current 2.40 version, though quite a few improvements seem to have been made on the animation side of things). But then I am not an artist nor a professional CG animator (or even a good amateur!). However, some folks are able to achieve amazing results, and I think it's a great introduction to anyone who wishes to get into the field - as a stepping stone to professional products like Maya and 3D Studio Max since the principles are common between them. Make sure to work through the wikipedia tuts and manual
http://mediawiki.blender.org/.
Herewith the obligatory fruit bowl - the "Hello World" of 3D.