We aren't sure if this new option appeared today with the newly-updated MacBook Pro, but it's the first time we've heard of it: reader Mark S tipped us off to the availability of a 750GB hard drive option in the iMac 24-inch and the Mac Pro. The massive drive isn't available in any other iMac (they still cap out 500GB), but with 4 available bays in the Mac Pro, they can now be configured with 3 terabytes of storage straight out the gate. That's a lot of iTS movies.
These drives don't come cheap, however: typical of Apple, each 750GB drive (across both machines) is a somewhat expensive $399 upgrade, so that's an extra $1596 just for the bragging rights of having the big bertha of Mac Pros on the block.
AppleiMac 27-inch with Retina 5K display (late 2014)