The Ferret first mentioned the Airpanel wireless display device from Viewsonic a while back, but now it looks as though Microsoft is driving the whole product concept into prime time territory. See this ABC News article.
They are basically TFT LCD screens with wireless networking innards which let you roam throughout a building whilst still being connected to your base PC. Neat idea and one that is likely to do a lot better than over-priced TabletPCs.