There are two units, there is the Surface Pro and the Surface RT.
The RT isn't something I would consider up to the task of doing much, it isn't very powerful and it doesn't run a PC version of Windows, so it only runs apps that will run in the metro UI. This basically means that an IOS, or Android tablet is much, much better in this price range.
The Surface Pro is basically a Windows 8 enabled laptop hardware wise, and it is much, much more powerful and usable, and I could see why someone would be interested in. I personally think one of the little touch screen enabled AMD A6 powered notebooks from HP are a much better bang for your buck, but perhaps less tablet-like than the Surface Pro.
I hate Microsoft in general, but I would say that the surface is built well, and doesn't seem to have any obvious flaws (a tough thing for me to admit), but I still decided against one for basically 2 reasons. The first being that ultimately I use a tablet to read on, and I don't care to use it for much else. The Second being that iOS devices play really well together, Apple TV, the Iphone, and the Ipad work together with a sort of synergy that the surface doesn't (Though with MS pushing their new phone I suspect they will try and do some cool things like this).
So, I would say a Surface Pro is quite a good device if you aren't heavily invested in Android or iOS, and you have a role you think it would fit well that a cheaper device wouldn't fit in better. So while it isn't for me, I wouldn't question someone for getting one. The Surface RT I can't really recommend, I only used it for a bit but still hated it's lack of power and flexibility.