There are some problems with comparing a Windows Surface Pro tablet to an iPad. The availability of programs is such that you're not going to use the iPad for content creation, and you're probably not going to use the Surface for gaming. The Surface is not a pick-up-and-go sort of device.
It's a laptop with a mutli-touch display.
I'm building a program right now for Windows 8, on Dell hardware[1]. I've gotten quite used to the OS by now, and as long as you have a touch display, it doesn't really deserve the criticism I've read. I remember hearing the same thing about Windows XP and Windows Vista and Windows 7.
The thing that I like the most about using Windows 8 is that all of my software just, like, works. A little bit of that is luck: if I had written any programs that had heavy use of keyboard shortcuts, it wouldn't work without a blutooth keyboard. If I had written any programs that expected the screen to never resize, that too would break. But those are pretty bad programming habits to begin with. My programs don't look great, but that is a temporary problem.
And I can program for it with the same tools that I'm using for Windows 7 (hell, I can program on it). I don't have to wait for someone to make a something-to-something-else translator to use my favorite language to write programs like I do on iOS or Android. I don't have to wait for someone to make a decent text editor on iOS or Android. I don't have to wait for someone to write decent source control software for iOS or Android. I have it all, already. I can do whatever I want.
Hell, if I want to install Linux on the thing, I could. Of course, it's probably not going to play nicely with the touch screen, but that is a different issue. The Surface Pro is just a PC.
[1] The Dell hardware isn't great, but it has a regular, ol', USB port on it, which makes it amazing. I've played with the Surface Pro at a Staples and found it to be better than this Dell device in every way.