I remember when 750GB drives were all the rage, but Hitachi's Deskstar 7K1000 drive has dropped my jaw. The retail is only 399! Several months after the 750GB drives became mainstream it wasn't uncommon to see them selling for 500. Along with the increased disk space, the 7K1000 features a needed buffer increase to 32MB.
Not to be outdone, Seagate confirmed that they will be making a 1TB version of their Barracuda hard drive. Both of these massive drives make use of PMR which I explained in-detail a while ago. I think it's safe to say that we will be seeing 1TB TiVos in a few months.