Just took exam 70-642 - Windows Server 2008 Network Infrastructure, Configuring. I was a little bit worried about this exam because manually calculating subnets and figuring out routing options was never my strength. That's what we have subnet calculators for, right?
Nonetheless, I passed with a 1000/1000 score. Admittedly, there was some luck involved here, because I had the feeling a lot of questions were about DNS and DHCP, and that was just the topic of the chapter I'm was recently working on for my Windows Server 2008 book.
Next on the todo-list: 70-640 - Windows Server 2008 Active Directory, Configuring.