Answers
1. "Has Apple prophet Steve Jobs just foretold the end of the desktop hard drive?"
No. Cloud services existed before he spoke.
2. "Seagate, Toshiba and Western Digital. The spinning disk gang are fresh out of luck."
You mean, apart from all the platters they will sell into the cloud biz?
3. "Smart phones and tablets are much easier to use than PCs".
Try leavng a comment this long using an iPad.
4. "Thus, consumers won't buy so many PCs"
Tablet and phone buyers will additionally buy a PC. Not all PC users will buy a tablet however.
5. "...users will abandon their PCs"
For a few minutes, until they have to create some content, ie. do some actual work.
5. ".. the expected loss of the Fibre Channel disk business"
Que ?
6. "The disk troika need, really do need, to find themselves new sources of growth."
Oh no! if they go bust, who will make all these new flash drives for us ?