I don't really like it. I don't think it will rise to the level of Google anytime soon.
Heck, Cuil returned 2.78 billion fewer results than Google did for the term "blog".
Yes, Cuil is new but I don't think it will acquire 2.78 billion more listings anytime soon.
Cklords, regarding the black saving energy:
This is only true of some CRT based monitors. LCD based monitors use the same electricity to draw black pixels as they do for any other color. However an LCD will use about 30% of the electricity of a CRT on average.
The Numbers Guy : Does a Darkened Google Really Save Electricity?