This article makes it sound like Wi-Fi-enabled video projectors are new: They're not, but the writer is correct that more are coming down the pipe. I wouldn't be surprised if, by 2004, all new projects had Wi-Fi built-in or as a simple add-on card. More important than Wi-Fi, of course, is software that allows remote laptop sharing so you can "log in" to a projector and have it mirror your laptop screen.
Linksys, for instance, offers the $275 WPG12 [Amazon.com], which is an access point and a projector interface. It has onboard Flash memory to store PowerPoint presentation for laptop-free playback, too, and an infrared remote control.