I was wondering the same thing, we are upgrading within the next 2 weeks also.

Make sure that you have alot of memory. I can't figure out who is winning the race with most used memory, Microsoft or Autodesk. About 12 years I was upgrading from izzycad 25 unix base software to Autocad or Microstaion pc based software. Microstion won hands down because of memory usage. We actually did a test where it took Autocad three times longer to do the same rendering than Microstation. From what I can see it is still the same way. Since installing 2009 I freeze up two or more times a day and have more recovery drawings that one could ever imagine. I have two gigs or ram and 7,200 rpm disk drive on Windows XP. Ive heard others say that they are going to bump up to 4 gigs of ram.

We just installed '09 on one of our machines. It seems to work ok so far. The biggest issue is there are some problems with plotting to PDF in which it won't print multiple sheets into 1 pdf file when using adobe drivers and not the ones included with Autocad. As far as speed I've noticed it is really slow when the ribbons are turned on, disable those and it seems to speed things up a lot.