I think that on the physical side, the Transformer family of tablets with keyboard dock is superior to what I saw from MS Surface. The Surface tablet seems a bit too flimsy to use without a solid surface to rest upon. I can use my Eee Pad Transformer on my lap very easily. I can also tilt the screen at any angle where as the Surface tablet seems to have a fixed angle.
On the OS side of things, the only thing that I still need my laptop for is for the physical storage (500GB), PC games, music (converting my LP's, tapes and CD's to MP3) and spreadsheets. For everything else, my Transformer can handle quite well. For most every day things like web surfing, social networking and communications, my tablet works as well if not better in some cases. I would say I only use my PC about 25% of the time while I use my tabelt 75% of the time.