I think he is referring to the notion that amazon could in theory discontinue the ebook/kindle line of products leaving him stranded without the books he paid for.

This is not as far fetched as it seems. Look at a few examples from the music business: Microsoft discontinued support for their music download service. Walmart did the same thing to their DRM laden music. Now anyone that purchased music with DRM from those two is sol if their computer/OS goes down and they need to reinstall. since they cannot authenticate to the DRM servers the music stops.

Solution to the music: use providers that do not want to cripple you. (Amazon MP3 download is the way I have been getting all my music.)

Solution to the E-Book: You could probably strip out the drm from the kindle protected books. It is probably against the law in some countries though.

Amazon is a book store, so their ebook service shutting down would be like Microsoft discontinuing Windows. Not too likely.

They do indeed discontinue windows just different versions of windows. What happens when XP suits you just fine but Microsoft decides that it costs too much to keep the activation servers running and you want to activate your legit copy of xp on a new machine. You are then forced to either:

1) Break the law and crack it. Doing this you will not be eligible for the updates that are there. In cracking it you are going to run a program that probably contains a virus/rootkit/trojan/whatever.

2) Reinstall the os every 30 days to bypass activation.

3) Need to buy/install a newer OS because you are at the mercy of a corporation with respect to DRM.

Amazon itself could shut down. If the recession has taught us anything it should be that we can't expect companies to be immortal.

If Amazon shuts down it means we've all been dead for weeks.