If this expansion allows team play with AI, I'll maybe consider buying it.
If it allows team play with mates, I'll strongly consider buying it.
If it allows team play with mates, as well as improving the SDK to encourage modders to experiment with coop, and encourage modifying the original game to be coop, they have the sale. This would be before a single screenshot was posted.
So long as they don't throw in extra added value like Starforce, they have a customer. I quite liked the original, however I do agree with most that it was boring and unimaginative in places, and it played the one trick pony a bit too long. Fortunate then, that the trick was a damn good one.