Once you get 2.1 loaded your backup time will be much faster. Also use this workaround to even speed it up more. As a matter of fact if your current back up is taking to long, kill it and try this. It really works.
Well documented way of getting a good clean backup at a reasonable speed.
http://www.iphonefreak.com/2008/07/q...he-backup.html
Works great for me. I have a 16g, with about 4gig used and 20+ apps. Takes maybe 5 minutes to back up.