First of all the game is pretty stable for a 0day version. Nice work and thanks for pushing it out on time for us.
System Specs:
Windows 7 x64
ATI Radeon 5870
AMD Phenom II 3.6ghz
4GB RAM
Ok now onto what i've noticed.
Graphical Bugs:
Border Colours - I've noticed a small glitch that happens when i conquer a minor race, the edge of my border changes to their colour, strange but not exactly game breaking.
Object displacement - There's a bug similar to something i noticed in Civ IV where projectiles (arrows/fireballs ect) randomly fly in from the edge of the combat area rather than from the tile the caster is stood on.
Sound Bugs:
The sound in general stops for no apparent reason, some times just the music/sound effects stop and other times there's no sound at all. This seems to correct itself whenever you finish research or one of your champions levels up and it plays the music with the notification.
System Errors:
I've played 3 games on a tiny map with a single opposing kingdom at easy difficulty. Every time i get near turn 200 i get a pop-up with the message "Out of Memory" and the game crashes. (good luck hunting down the memory leaks, i know they can be a real pain to find in something as big as a game engine)
That's all i've noticed, i'll edit the post and update if i find anymore.