Just done the update to WordPress 2.8.
Tried the auto upgrade feature and it wouldn’t work at first, just kept getting stuck at the “Unpacking core files” bit. After a little bit of digging, I then deactivated ALL plugins and retried. Worked perfectly at that point. Then just a quick reactivation of plugins and Bob is your mothers brother!!
First impressions are that it is noticeable faster in all areas, a welcome improvement. And I would therefore assume that it will put less of a load on the web server as a result.
It can be downloaded from wordpress.org or upgrade automatically from your admin panel!