Well I played the demo (162Mb) of Rome: Total war yesterday lunch time, I was pretty impressed, you get a simple training mission and the historical battle of Trebia where you play Hannibal with his elephants.
This was pretty good, but considering that the battle engine of Rome:TW has already been used on two historical re-enactment type TV programs I already knew it was gonna be pretty damn good.

The part of the game that I’m looking forward to seeing wasn’t available in the demo. This is the re-done campaign map, it is enirely in 3D, with the ability to zoom in and out. A more exciting aspect of this though is the fact that representations of armies on the campaign map are possitionaly accurate. In other words, if they are ‘near the river on the left’ in this view then thats where they’ll be in the battle view. Also armys can be possitioned to cut off trade routes and other such things. The representation of cities will also be accurate, with buildings destroyed in battle being no longer available in the campaign. ie if a barracks gets destroyed then that town will no longer be able to train troops.

Gamespy have a very good hands-on preview, although you do have to get past some advertising first 😐