The fairly popular IntelliMouse Explorer series, which hasn't seen a new incarnation in several years, will soon be making a comeback. Microsoft is looking to release the IntelliMouse Explorer 3.0, featuring the high-resolution tracking and high responsiveness that made the original IntelliMouse popular, despite its very simple appearance. The IntelliMouse is sought after because of its relatively medium cost and its excellent performance in high speed games, making it very popular among gamers:

Microsoft says it brought back the mouse after three years due to popular demand. The company began to get wind of gamers' preference for the IntelliMouse's button placement and clicking scroll wheel via the blogosphere and game conventions, said Jolene Cramer, lead marketing manager for Microsoft's hardware division. The response "kind of astounded us," she said.
With a 9000 frames per second resolution and a built in cursor tracking system, along with its $39.95 price tag, it may end up quickly becoming one of the most popular mice around. I've never been disappointed with the IntelliMouse in the past, and I doubt I will be this time around.