I used to verse the AI a lot before I finally decided to make the leap to online play (very different, I can assure you).
Ususally they will (on regular supremacy) build themselves up for the first 10-20 minutes if you leave them alone, then start harrassing you a bit with small raiding parties and a foward fort.
Then in the late game (assuming you leave them alone) they will launch massive assault after massive assault at you in attempt to bludgeon you into loosing.
I don't really know how they respond to rushes as I am a turtler/boomer (that's why I switched to treaty as soon as I started playing online), I cannot rush and I cannot survive a rush.
However, if you start pwning them in the lategame you can expect them to focus on rebuilding with fully upgraded towers all within range of each other around their base and units just idling around (once you land a few solid attacks on them and repel a few of their massive ones they just stop attacking pretty much).
[This message has been edited by anterior2 (edited 08-28-2010 @ 02:02 AM).]