An article from eWEEK Intel Starts an 'Apple Group' indicates that Intel is taking this Apple thing seriously. This is probably the best indicator yet that Apple will introduce Intel-driven Macs sooner rather than later:

Industry analysts and others have confirmed that Intel Corp. has formed an internal "Apple group." This group, formed in the wake of Apple Computer Inc.'s decision to base its next generation of Macintosh computers on Intel processors, is comprised of engineers and sales staff.

Intel has similar groups for other large clients such as Lenovo and Hewlett-Packard. Specifics on the Apple group are sparse, however.