The current version of WindowBlinds on ObjectDesktop.net is 3.19.
Here are some of the things it does that are of interest:
1) Global bitmaps. Can actually thank Gerhard for this one. WindowBlinds 3.1 and earlier loaded all the bitmaps on a per process basis. That is, when you load up Internet Explorer, WB would have to go and load up all the bitmaps associated with that skin. This is what we believe causes some people to feel WB makes their system "feel" sluggish. If one has a slow hard drive (or is using NTFS with compression on it) this can be a significant issue. This eliminates that problem and also makes switching skins much faster. This also makes it use fewer resources on Win98/ME. Bottom line, WB now loads apps faster than if using Windows XP's visual styles.
2) Full version now skins IE completely.
3) Start menu logoff/turn off buttons now skinned.
4) Tasks panel in explorer windows keeps XP look (we don't skin it yet, have to decide how we want to do it but it doesn't look like classic).
5) Misc video acceleration support (automatic).
6) Bunches of othre tweaks made for skin authors and for increased compatibility reasons.
7) Uses the XP visual style engine even more so now than previously.
There are some other things we're working on that may make it into 3.2, will keep you up to date.
Overall though, 3.2 should be a big win for Win98