Estimated mining power by October:

Minimum: 100TH AM + 100TH Avalon + 300TH Avalon chips + 200TH Bitfury + 300TH BFL = 1PH
Realistic: 300TH AM + 100TH Avalon + 500TH Avalon chips + 500TH Bitfury + 1PH BFL + 500TH KNC = 3PH (actually up to 5 or 6 with all upcoming hardware)

Revenue per GH per day: from 1 to 4 mBTC

Lifetime revenue:
The very best case (totally unrealistic) scenario: 1PH by October and 10x growth per year after that: 0.6 BTC/GH
Much more realistic case: 3PH by October and 100x growth per year after that: 0.1 BTC/GH
The worst case: 6PH by October and 1000x growth per year after that: 0.03 BTC/GH

P.S. Conclusion: why would I ever fuck with mining? CoinLenders pay 25% APR, JustDice currently about 10% per month.