So does this also mean that they are going to stop production on mobile Momentus XT Solid State Hybrid 7200rpm hard drives too?

Spinning drives will become more and more obsolete, as prices for SSDs come down. Its obvious. My first hard drive cost $3000 for ONE GB.

Seagate may eventually move to non-disclosure of rotational speed. Seagate already sells the same item number with different rpm drives. Should Seagate be allowed to change the rotational speed of the hard drive and not change the product's item number? Seagate's STCA4000100 is a 3.5", 4TB, external drive. But inside is either a 7200 rpm or 5900 rpm drive. Seagate's choice. Both sold as the same item, STCA4000100. If the rpm of a drive was ruled a material specificaion of what was being sold, then Seagate may already be in violation of contract law. Some may remember when Cadillac was successfully sued after substituting Oldmobile engines in product sold as Cadillacs. At least the Oldmobile engine substituted in Cadillacs had the same specificiation. Not the case when a 5900 rpm hard drive is substituted for a 7200 rpm drive. A good call action lawyer would have a heyday.

http://www.youtube.com/watch?v=L54h9_2NO5Q

OK, so future Momentus XT drives will be 5400RPM instead of the current 7200RPM with some NAND flash?
I doubt that, it's their performance drive. Until they stick a lot more cache on there that can also buffer writes, 7200RPM is needed to maintain decent performance in all situations.