Year Of Linux On Desktop?

Every year we read about "the year of Linux on Desktop", but those articles always seem to fail to explain how do they measure it. What does have to happen for us to definitively say "this is the year of Linux"?

Here's some data...

Market share growth from November 2009 to November 2010:

Micrsoft OS's: -02.77% 
Apple OS's:    +30.86% 
Linux:         +53.00% 
(using this statistics as a data source)

I don't know what "Year Of Linux On Desktop" means, but I, for one, see a winner in 2010: Linux.