I was also curious about the 1.1 update but didn't want to lose root, so I went ahead and tried out the
pre-rooted update. Turned out to be very painless -- all my apps and their data were maintained.
[The notes say adb is lost, but seems to work for me. I did use adb wireless though (and then checked usb). Shrug. Update: they don't say it anymore, the report of adb failure was user error]
But, I'm not sure I find the advantages worth it. The pinch-zoom in stock browser is indeed not as smooth and responsive as it should be. First boot is slow, but subsequent ones went faster.
I am happy to have now switched to clockworkmod and to have a nandroid backup, though.