Third party retailers delay after new product launch?

[KerryH]

Hey guys, I've just sold my main machine and am using a temporary old machine until haswell drops and the air is refreshed.

I'm wondering, how long after the launch date of a refresh do the third party retailers (amazon/macmall etc) get the updates?

The difference between paying shipping and tax from apple and not paying shipping and tax from say amazon is pretty substantial in my eyes on a ~1200 dollar machine (what I intend to spec out around)

Thanks!