My conclusion is that making predictions about mining is very hard. I hope, like many others that i'll be able to mine enough BTC with my 50Gh/s before the difficulty skyrockets. But i think that in the long run the investment in a miner is smart. Even if all the coins are mined, there are still the fees.
Also even if the difficulty rises, so does the price. So i'm hoping for a "steady" pay-out.
My greatest choice to make is which mining pool to join

I hear you. I was reading something about 50BTC having close to 50% or more of mining power? I'm going to make a special note NOT to choose them.