I have been doing some major reworking of matchbox wm internals specifically the window stacking and focusing code. Much of the code for doing this kind of stuff was really basic and unchanged since very early matchbox versions. With handhelds nowadays having quite largeish resolutions, people have room for more complex multiple dialog setups ( rather than the single dialog per app palm os type model matchbox originally aimed at ). The old code, though it worked, just didn't work that well imho. The rework has made something more flexible and powerful yet so far uses less code. So I guess the amount of time and pain involved to get the rework done has been worth it... Expect it in the upcoming mb 0.9 release ( with other goodies ).
The Firefox Live-CD appears to be using matchbox - cool!
SoftGun is an interesting, linux booting, software emulated piece of ARM hardware.