I have a theory that over the next few months the difficulty might not increase as much as expected as ASIC units ship to consumers. Basically I think these machines are already online. So when they ship from KnC, BFL, BitFury, Avalon, they aren't really going online for the first time.

Any way we can really know if the ASIC miners are mining already, or do we just take their word that they'll ship as soon as they physically exist?  From the company's perspective shipping without mining a bunch of BTC first is like throwing money away.