I think some musicians keep and play guitars (and amps) they like while others play those brands they have 'agreements' with. Many others do both, I bet.

Another question that arises from Mayer's earth-shaking news ;) is what is Fender's role in all of this? Or another company's? Did one deal sour while another grew sweet? I can't imagine any pro ditching a brand in toto when we all 'know' that individual instruments have individual sounds sometimes quite independent of their logo and musicians often have long-term love relationships with individual guitars.

Maybe PRS is offering an individualized, custom treatment to Mayer. I know PRS does custom amps for musicians...tweaking for the sound they want...maybe they do so for guitars as well.

Kinda related... I noted with surprise the absence of Fender guitars at the McCartney concert this summer. I counted 14 guitars played by Paul [U]and[/U] his band and not a Strat or Tele in the group. I'm not sure that means anything/is meaningful but...given the since-forever pervasiveness of Fender in pop and rock I was surprised.