Also, keep in mind that BFL has touted the ability to produce 400 devices a day in the very near future. At that rate you could probably order a device and receive it within a few days. What that also means is a serious dillution of existing and future rig profitability, and in my opinion, huge price drops. Avalon and ASICMiner may not be able to compete in a price war with BFL, but BFL may end up having one with themselves if sales start to slow.
If BFL actually shipped 400 60 GH/s units per day, they would be adding 24TH/s to the network each day. In 3 months, the network hashpower would be 2200 PH/s (plus all the other ASIC supplier shipments).
Your super SC would be generating less than 0.1 BTC per day. And you can expect that ASIC suppliers would be dropping their prices so they could continue to sell hardware, further eroding your income over time.
Of course, BFL's track history makes it much more likely that they will struggle to ship 10 units / day. In terms of placing a new order, that means you can expect delivery sometime after the next block reward halving.