of course they will be slow with shipping and not ship anywhere close to the numbers they were suggesting (400/day)... it's BFL.... It took them like 6 months+ to ship all their FPGA preorders. I'm pretty sure they have more ASIC preorders than they did FPGAs because they've been advertising like crazy since day 1. So... I'd say AT LEAST 6 months for them to make it out of their preorder backlog, probably more like 9 though.
BFL only caught up on their FPGA pre-orders because they discontinued the product and instead started taking ASIC pre-orders.
They started taking ASIC pre-orders (and effectively killed the FPGA market) in June (or was it May?) 2012. They shipped their last FPGA Single in November 2012.