Scanii.com (https://scanii.com) practical API for malware/virus detection. Low thousands/month and growing quickly, profitable from the beginning and we effectively spend $0 in marketing. Honestly, there hasn't been an easier time to do a startup or side project - I know that's cliché but it isn't. If you know how to consume cloud services you can keep your operating costs amazingly low.
Its a 4 minute demo. If you've ever tried giving a business pitch for a new company to an investor, you usually have even less time. What they are doing is hitting the high points, i.e. Windows kernel on ARM, popular applications already running on the new kernel, and device integration (printer, phone, etc) with the kernel.
I'm not a big Microsoft fan, with the exception of Xbox and the new Kinect. However, you have to give credit where its due sometimes. I am blown away that the little motherboard he held at the beginning is so little. I've seen UMPC devices (my roommate had one) that ran Windows on a little piece of hardware, but very poorly. This so far looks much more impressive than that.
So while the demo looked fairly basic, you really have to step back and understand the hundreds of man hours that it took to get the core Windows kernel ported, plus drivers, plus applications. Building this stuff is not easy, no matter if we dislike the final products or not.
