I got the official update to Froyo yesterday. It seems largely the same as the older version, but with a couple of additional apps. Over my WiFi it only took a couple of minutes to download the 90M update, although it took something like 10 minutes to do the update, with several reboots to complete everything.
It has a video playing app now, which means I can dump the one I installed. An amusing app is a flashlight, which allows you to use the cameras "flash" as a torch, with three levels of brightness.
It looks like the battery usage is a bit better, although it's hard to tell with only a days worth of use.
I've managed to use some flash applications, BBC iPlayer, TVCatchup, and YouTube, which all seem to work fine.