That is the big question on everyones mind, and here at the Inq, we aim to please, so we will tell you. The short answer is Optiplex 740 on November 6th.
There are two replacements for the current Optiplex 620, the 745 which adds a Conroe instead of a Pentium 4, and the 740 which adds AMD to the mix. You will see 745s in a few weeks, and 740s a few weeks after that.
The prices we were shown say that the AMD boxes undercut the Intel ones, but not by a huge margin. Now you know. µ