As ASICs come online, the difficulty is going to go up, which will reduce the daily generation rate for any given miner. I've been trying to decide whether or not to order a device now based on my profitability prediction for months from now when I might actually get it. I'm guessing by the time I get one I might be able to produce at least 0.05 BTC/day. Assuming that's $6/day, the $274 device will take about six weeks to pay for itself. Not too bad, but I don't know if keeping tabs on it afterwards is worth it for $6/day. It'd only be worth it if I think BTC are going to be worth a lot more in the future... getting back to hoarding coins as an investment rather than using them as currency.
