I only started a mining a month ago and difficulty has gone from 12 to 19.3 in that short period.
Will difficulty rise so quickly that single GPU miner's like me will have no profit all? Especially when ASICS become widely available. I only started as an experiment.
Soon only the rich will be able to mine - Ah capitalism!
Your thinking is flawed. If I invest 500 dollars into mining hardware, I might realize X% return over say one year. If I invest 5000 dollars into same hardware, I will be realizing the same X% return over the same period. Sure, vendors provide a certain discount for higher-priced hardware, but this is insignificant compared to other variables and unknowns, plus is easily addressed by buying shares in a large mining operation.
Mining is currently a level field for all, rich or poor. Even if and when Bitcoin becomes big enough to spawn specialized mining firms who develop proprietary ASICs for exclusive self-mining, you could still participate by means of a mining co-operative or a publicly traded company, or a partnership...