We attended the Microsoft demo night at their Irvine Offices and what is coming out in terms of touch capabilities for Windows 7 is way better then I expected.  They were using a HP TouchSmart TX2 to demo Windows 7.  In Windows Vista, multi-touch is minimally supported.  There are no useful gestures like pinch and swipe. HP's TouchSmart application that handles images, video and other multimedia does support multi-touch and you can pinch to zoom, swipe to move to the next picture and rotate images. Windows 7 which adds strong support for capacitive multi-touch displays and makes it similiar to using an iPhone. The OS and MS programs support inertia scrolling (a long, strong finger swipe scrolls the page further, faster), pinch zooming with two fingers, rotation with two fingers, painting with up to 10 fingers in Paint. You can see in this video where I whoop on @Jraya that once you get the hang of it works quite well.  Although, there might not be as many touch points as there are on the Surface (200+) it is quite similar.

Depending on the programmer some applications could be compatible with both the Surface and Windows 7.  Microsoft is trying there best to get developers to make their applications touch compatible.   Here we have Woody Pewitt, SoCal Developer Evangelist at Microsoft, expalining the API's of the Surface and Windows 7

Lynn Langit (SoCalDevGal) is doing a Windows 7 Developer Series on her blog, that is a must read if you plan on doing some development for the Surface or Windows 7.  You can find it all here on her blog.