Microsoft has finally released Expression Web Designer (Codename: Quartz) CTP1 . I plan on spending some time with it real soon. From the screen shots I've seen the interface will be familiar to anyone who has ever used a Visual Studio product. Which to me is great. It also looks like Microsoft have really made some great improvements in the ways of website design tools.
System requirements include .Net 2.0 and a min XP SP2 … but honestly what hasn't in the last few months.