If you're trying to configure an iMac
system to arrive in time for the holiday season, you'll have to cap your storage at 1TB. Next day shipping is available on iMacs with a 1TB mechanical hard drive, 256GB solid state drive, or 1TB HDD + 256GB SSD from the Apple Store, but if you choose one of the 2TB HDD options, you'll have to wait 5-7 weeks for it to ship. That would put the arrival date at anywhere from the middle to end of January.
Such a long lead time isn't par for course when ordering an iMac, but apparently even Apple
can't escape the ripple effects of recent flooding in Thailand. The overseas floods ravaged the hard drive industry, ultimately resulting in a shortage of HDDs, higher prices, and in cases like this, long delays, at least for home consumers.
Those in need of a workstation-class machine can order a Mac Pro from Apple with up to four 2TB hard drives and it will ship in 3-5 business days. This tells us that whatever remaining stock of 2TB hard drives Apple is sitting on, it's being set aside for business clientele.
Back in October, Apple CEO Tim Cook admitted he was "concerned" about the hard drive shortage, but also said he wasn't sure how it would affect Apple.