I don't think Apple would create such a tangled web of disparate connections, products, and functions just so they could push their new iTablet as a digital media hub and portable screen. I mean, Crestron has had large touchpad uber-remotes for years, and there are Windows devices which are ready for such things. Viewsonic's $1000 porta-screen lets you surf, click, yadda yadda yadda from the comfort of your couch, bed, etc.
To have these two technologies converge isn't too hard, but to entice Tom, Dick, and Harry to buy the miscellaneous equipment needed to connect such a convergence device with the rest of your home is no small chore. Ideally, electronics makers would gradually phase home networking into their devices (WiFi, Wireless-G, etc.), standardize their connections (e.g. FireWire home theater), and put everything on an easily accessible, yet very capable, modular network.
Only then could Apple release a blockbuster product that lets users access this already-established network five times easier and more reliably than competing technology. (and encase it in brushed aluminum and white-backed Lucite😀 )
Of course, such a product would come at no small price.
Persuading people who are uncomfortable with/unaccustommed to the network itself to buy such a thing (iTablet) for "convenience" and to one-up the Joneses is another nightmare in and of itself.