I am getting a MCSE and Security+ degree. O_o. I've only taken 3 Linux class in my life time. I don't think that Win2008 R2 (kernel 6.1) would make too much difference from Win2003. This is why pros need the latest OS due to 'security holes'. I won't care unless this means my job, it'll probably come to that too.
I still believe Windows Vista/7 is great for gaming.