Omnitopia Dawn (Diane Duane)

This story is about MMORPGs and corporate espionage. Omnitopia, a hugely popular gaming system of a great many interconnected universes, is poised to roll out a major expansion, but lots of competitors and hackers want to make it fail. The man who runs Omnitopia is an all-around great guy (too good to be true, actually), and leads an amazing team of folks in defense of his world and the players. I was really caught up in the whole battle, especially with all the fantasy elements they use as metaphors while fighting. The ending was a little overblown, where it wasn't predictable, but it was still a fun trip.