Just a quick note (I have more posts on the way in the following weeks, but I've just come back from almost 3 weeks of "downtime" so my backlog is huge)
As announced earlier WBH 4.5 and WBH for Applications 1.5 was in beta, but they are now released. You can find further info on what's new in the earlier post.
The Microsoft Solution for Windows-based Hosting version 4.5
The Microsoft Solution for Windows-based Hosting for Applications version 1.5