i don think they ever want to deliver
Wrong. A lot of people have received their BFL equipment. Hell, I got mine back in july, mined for a bit, then flipped them out to local buyers for about a $1600 profit.
Not saying that BFL aren't a bunch of incompetent, sneaky, misinformationing bastards. They are. But people still harping on how BFL will "never deliver" when they have clearly been delivering for months is just retarded, poorly-informed ignorance.
But BFL eighter are bunch of incompetent, sneaky, misinformationing bastards or they delayed the shipments and mined themselves. They have to ship in second cause as well because the miners use so much electricity they could not mine with more miners anyway
I don't think they are doing extensive mining with units before shipping them, but that's just my opinion. A 24-36 hour "burn-in" test of each unit is not unreasonable. If they were mining for weeks with each unit before shipping, and proof of that was made public (to my knowledge, no such proof of massive mining with customer units has been shown) the backlash from their customers, their detractors and the bitcoin community at large would be pretty severe. Right now, it's pretty well confined to a relatively small group of vocal opponents here on bitcointalk, who talk of potential lawsuits, class actions, etc etc.
It's (to me) more plausible that they are just incompetent and lack the manpower/skills to produce more units at a faster pace. Again, just my opinion.