agree with fatalsaint.

I think that, as government and private entitiies looking for ways to reduce licensing costs in their desktop environments, move to open source, it will be seen in the wider, home user community as a familiar and viable alternative.
The major distros have all come a long way wrt ease of install and set up, but to I personally believe that the "netbook" craze will be the catalyst for a greater uptake in the home desktop arena.
As manufacturers start to see the benefit of using *nix base OS's, they will hopefully start to ship desktops with Linux alternatives.
Most home desktop users walk into their local computer shop looking for a turn-key package that they can take home and plug in. achieving greater "market" share will mean convincing the big PC makers that Linux can do achieve this on the current (or future) hardware platforms...

just my 2 bob