Being just free-lance is not the right way - it will result in a mess. Do it right from the start.
Twitter is closing down it's API. I can see how the ambitions can drive you to become more than just the infrastructure - but there lies also the trap.
While I think that businesses are going to skip Windows 8, I don't think that Metro will be going away. I would even say that the desktop will be gone completely in Windows 9 and that businesses will love it.
Facebook for example has become big enough to swallow all upcoming and already established competitors. After acquiring Posterous, now Instagram.