Deep purple, plum and lilac are the in polishes for Fall 2011.
Metallics are making a comeback for the winter.
Here are some of my fave's:
Essie "carry on" is a great deep plum purple. It's described as a deep burgundy but I think it's more of a plum.
Essie "lady like" is a lilacy mauve.
OPI "diva of geneva" is a great deep metallic purple.
OPI "the color to watch" is a metallic very light pastel lilac.