I imagine that a computer's ability to control units with instant reflexes and frame precision will make AI Starcraft a completely different game from anything we've seen. Watch some Tool Assisted Speedruns and see how the gameplay of a person playing frame by frame transcends that a skilled human playing normally. Games are designed, tested, or balanced with the expectation that a player cannot press a button thirty times a second, anticipate the frame in which a projectile which hit, or issue commands at ten map locations at once. Without these limitations, the game can be broken and become something the designers never intended.
I expect the contestants to abuse lots of bugs and glitches exploitable only with frame-perfect control. For example, there's a known bug when about 1% of the time, a dragoon shot will miss a moving SCV (with no high ground or cover). If something like this can be consistently reproduced, the game will warp. Another rare bug has units become stuck while moving past each other, causing them to dart at ridiculous speeds in a perpendicular direction. This is likely reproducible, and could become the main mode of unit movement in this contest. Even if this doesn't work, there's probably a way to move faster by issuing rapid commands in a way that takes advantage of animations, since Starcraft ground unit movement speed is not hardcoded but animation-based.
Even without bugs, an AI could dance around ranged units to be basically invulnerable to melee, or any slower unit with lower range. This will give Terran a powerful rush strategy (how ironic).
Imagine a game of Terran versus Protoss. The Terran builds a fast barracks, and sends two three marines at the Protoss base. By then, the protoss has two zealots, but they won't matter, since they'll never get a hit. The Terran player dances the marines to shoot the zealots while taking no damage by always moving whichever two marine are being chasing, while the third is free to fire. Even against an equal-sized zealot force, marines are slightly faster that zealots, so they can shoot and move with impunity. The marines can slowly make their way into the Protoss base and behind the mineral line where they'll slowly wear down the mining probes' health, even as the Protoss makes focussing on any one probe impossible. The Protoss might try to get a surround with probes, though I think the marines will escape. Even if the Protoss fends off this rush, the Terran can have vultures before opponents have dragoons and wreak havoc with them.
Since zerglings are faster than marines, I'm not sure if this strategy would work in TvZ, though we might still see some epic bunker rushes.
Note that I don't think this distorted gameplay is bad, just different from human play. I rather like the ridiculous perfection, timing, and bug-abuse of tool-assisted speedruns, and look forward to seeing what the contestants come up with. I would love for a contestant to find a strategy that completely breaks Starcraft as we know it and wins unopposed. However, I think those who expect the final matches to look like really polished high-level human Starcraft play might be disappointed.