Man, if he thinks debian is going to go by the wayside then slackware is doomed.
I am a slack fanatic. I love slack a lot. But I recognize (as should most) that slackware is not something slightly computer literate people could easily install. Redhat, yes, they could probably manage RedHat, since it is a much easier installation than Windows is.
The biggest hurdle linux faces is getting onto existing desktops. The vast majority of computer users don't reinstall their operating systems, they just keep using and using until it's time to upgrade for that new version of windows (although, that is changing as more and more kids grow up using computers). To get these users to install linux should be no harder than installing Office (since most users I would venture have installed software at some point or other). Linux itself still has a bit of a ways to go before it can start to eat away desktop market share, but because of the way it is designed, and its capabilities, I would venture it can make it further into the ease of use realm than Microsoft and Apple ever thought was possible. I think this for a couple reasons, but mainly hardware support and the ready availability of a large number of drivers.