After a bit of CCS and a bit of WF, my latest project is on WPF giving me a chance to use the tools and start to understand how to architect real solutions around the libraries.

I don't think the flexibility of WPF can be underestimated - with all of the increasing possibility of templating, styles and binding and therefore how these all interact. There's also the split of XAML and C# to consider. So from a developer perspective, you can achieve all sorts of things - SeeWindowsVista - and from an architectural perspective there needs to be careful consideration of how to assemble a good WPF solution. I'll be pondering this over the next couple of months.

Given that I can't draw a straight line with a ruler, it's also very handy that I'm working with Martin Grayson, who is a resident expert and blogger on the subject of WPF.