What we need is....
a very simple portable display around A4 size that contains the bare minumum of electronics to do the following.
Connect to a host system via mobile and / or consumer wireless.
Display either the screen of the host via VNC, or a screen generated by an application or service running on the host.
Sound can be provided if required using streaming from the host
The host would be a basic home pc with a network connection
Host resolution can be provided using dynamic DNS or IPv6 when it eventually turns up.
Very cheap as only minimum components are required
Very long battery life in comparison to existing tablets as processing requirements are very low.
Long life, system should not become obsolete as the host can be upgraded with new applications etc.
Totally open system, do anything you like with it.
Run your desktop / any application from your host machine.
No need to worry about syncing files to your device
Only 1 security interface to worry about exposing to the internet.
Few updates required as the software is so simple
Requires network access to function
Has probably been patented
Apple will try to kill it
Network speed may prevent playing of fast moving games
Cost: around £200 - $150
Reasoning, if you can get a 11.3 inch portable dvd palyer for £179 you should be able to make my device for less.
Somone please mass market one of these, i dont have money to do it myself as i spend it all on beer.