John Mayer, and his solos

ok, so everytime i see john mayer, i'm amazed because when he solos to an upbeat rhythm (all the time), he just strums all the strings and mutes all the strings except the one he's playing. to me it reminds me of songs like cold shot by SRV kind of following that style of soloing. is this an illusion and if not, how does one acquire the skill of comfortably playing and soloing like that

It's just something that developes over time.
Whenever you're playing a lead, you always have to think about what strings aren't being played and learn to mute them all the time.

He has a very developed style. You can see the obvious resemblences of his style and Stevie Ray Vaughans style... But truth be told when John was younger he wanted to be a metal virtuoso. Instead the blues got ahold of him and now he has the style that we've come to know. Like Schmange said... its a comfort thing. He gets in a groove and just plays. Its something that you have to mess around with to be able to know what sounds good and what doesn't.