I know 2 TBs are a ways out (at least for mere middle class folks) but I don't *use* 2 TB drives.

A 2 TB drive with 64MB cache and NAND could be incredible.

Quite to the contrary, USB as a HD interconnect is the one that's not practical - tried backing up a 1 TB drive over it?

In fact, according to this page on the Apple website, 2008 Apple iMac computers can be ordered with 1 TB hard drives.

Apple is offering the Promise SmartStor DS4600 RAID system alongside the mini for $799 with four 7200-rpm 1 TB drives, and two FireWire 800 ports.

The DroboPro has the increased capacity of 8 drive bays rather than 4 in the original model, giving a 32 TB theoretical maximum with the current 4 TB drives.

A one-terabyte (TB) drive was unveiled at the 2013 Consumer Electronics Show and will be available during 2013.

I paid about $80 for my last 2 TB drive and I only paid that much because I could not work up the energy to send in the rebate.

Now you are doing well to get a 1 TB drive for twice that money.

The XIV Gen3 model offers 3 TB drives, providing up to 243 TB of usable capacity per rack.