Just ran an update to 3.0 on my Iphone.   Seemed to go through pretty smoothly.  I didn’t time it, but would say it took about 20 min.    You need to upgrade to the latest ITunes first though so that takes a little while + a reboot.

Noticing a few tweaks here and there, but I think I’ll really need to use it over the next week or so really start seeing the difference.

Nice touch that you don’t loose all your settings when applying the firmware update (as I’ve seen many times on Windows Mobiles).