MacRabbit just updated CSSEdit to version 2.5, which brings some new features such as tabbed windows and the X-ray inspector for all of your CSS needs. I’ve been using this quite a lot since the 2.0 release, the new features have been very helpful with development; I can’t recommend this program enough.
Panic just released Coda, which is an integrated web development solution, part Transmit, part SubEthaEdit and Terminal, with CSS support all rolled into a single interface. Personally I started on Dreamweaver, but dumped that for a combination of Textmate, CSSEdit and Transmit for all of my development needs. I think Coda can give Dreamweaver a run for it’s money, Coda is a much more affordable solution for a freelance developer.