100,000 chips is 7.5*100,000 = 750TH/s. Unless there's a significant price increase (let's all hope), then that takes just about all incentive out of buying ASICs once those chips are eaten up. Payback would be around a year at that point... fairly risky in the world of Bitcoin.
I'm feeling it now for those who ordered early. With BFL's much bigger initial chip order the difference in delivery time between the first to order and the last is not going to be very long if they send them out soon-as-built meaning the big-returns widnow is likely to be short-lived as the ASIC hashing power goes through the roof. Profitability is not essential for me because it's as much novelty/supporting the project than anything else but to the extent that I am counting profitability it is versus returns in pounds had I simply bought Bitcoin instead. BTCGBP was about £6.80 when I made my BFL order (being now around £7.80) but those who put their money in when BTC was much cheaper have not only lost out on the raise in Bitcoin value but will also have little reward over latecomers in terms of getting an early advantage with mining. I really hope it works out for everyone but it's looking less likely by the day.