There's a new CTP of WinFX bits available, however there's nothing new for WPF (Avalon). But if you are working in WCF (Indigo) or WF (WWF) have at it.
It would have been nice to have a little more functionality in Cider, but considering everything, I'm sure that we'll see some more interesting bits in a couple of months. And speaking of interesting, how long till we start to hear about WPF/E? I'd love to see Live gadgets using WPF or WPF/E.
UPDATE! - There are updated Cider bits! From the mouth of Tim Sneath
Secondly, it's worth pointing out that this release doesn't actually contain any changes to the WPF component. We've been working on a separate branch and for various reasons that have to do with integration with Windows Vista, we're not easily able to expose those changes in this release. There's a lot of platform work that we'll make available soon - hold tight! On the other hand, there have been improvements to the SDK and of course the "Cider" integrated tools in Visual Studio are a great improvement on the basic facilities that were available in previous releases. The good news is of course that any code you've written or downloaded for the December CTP will run quite happily on the January CTP!