In full support of this decision. He came into clay last year looking like junk. Managed a trophy and three finals, two of which showed clay-hope against Nadal. Then he won Halle and nearly won Wimbledon. Would anyone have predicted that after Miami's loss to Roddick (or the Fish loss in IW)?
It was also suggested that Fed skip USO '08 after the Karlovic Cincy and Blake Olympics losses.
He could rationalize his losses last year because he had mono and lost a lot of preparation time.
He has no such issues this year and he said so in the interview after his loss in Miami. It seems to me that he has no clue why he played so badly against Novak and without resolving that, he might get into another pressure match and break down once more.
With a month at his disposal, he could potentially seek out an experienced coach and use that person as a sounding board - maybe even turn his complete attention into the process of hiring a full time coach.
That, in my opinion, is better than playing at MC and hoping that his game magically clicks.