Paypal isn't going to stand by and leave BFL's account in good standing while they take hit after hit of chargebacks. A run of Paypal chargebacks and then BFL stops accepting Paypal. I think there's a connection.
Personally I think they saw money flowing out of their coffers. The difficulty made customers realize that they were totally fucked on making ROI.
They (BFL) probably decided to launch the next project and announce it as fast as possible. CGI render in place, check.
Sales Pitch: Oh wow, look at this, we are making a 600Gh/s PCIe card!
They did it so fast they didn't even have time to write up a press release. They just announced it on forums and such, as far as I can see.
BAM, the flood of funds starts to come back into the coffers.
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Like lemmings its not unexpected that customers ran for the next offering. BFL probably wanted to clear the older orders and transfer them into an offering some months into the future.
They killed like three birds with one stone.
--Take Paypal off their site. Eliminating PayPal oversight.
--Give themselves a legitimate excuse to stop chargebacks.
--Reduce the liability they have hovering over their heads from Gen 1 not being delivered anywhere near on time.