Oh how quickly the past is forgotten :) In early 2000s, microsoft, through its partners, tried releasing remote displays powered by windows CE - they were essentially a precursor to the tablet. Several devices were exactly as you describe.

http://www.roughlydrafted.com/RD/RDM.Tech.Q1.07/50755EA6-A75...

Im surprised it took over a decade to get a device that doesn't suck in that form factor, but im glad it happened.

Will be preordering one tomorrow! edit: this post was written on an MBP :)