I used a web app called SnapTax one year in Canada to do my taxes. It was easy and fast, ahead of its time for web UIs, and showed what much better technology can do in the space. Intuit bought them and killed the product. Their own product (needless to say?) is awful.

If all you want is to get acquired and you don't care about your product being killed, making usable tax prep software is probably a good way to go. Unless there are regulatory barriers, it doesn't seem particularly hard. You'd have to immerse yourself in tax details, though, plus not love what you were doing.