That's way more than I'll need in a lifetime. 500 & 320GB (I have both) is fine for me. You know, just a few short years ago, many of us had 20 & 40GB main drives in our notebooks & PC's. Now, the sky's the limit. It would not surprise me one bit to see a 5TB drive by the end of next year, mabye sooner.
You know, if one had a business, yes I could see all the extra space. But what home user really needs 3TB? Sure, they'll sell, but it's more of a "my thing is bigger than yours" deal. Mine are less than 10% full, and I don't have a total of 1TB.
What I really want to see are those SSD's going into main production, where they can build a 320GB or so one. That would be all I need. Just wait, another 5 or so years, they will get larger, and cost less. At least that's what I'm hoping for.