You need to discover your feminine side, MLCM.
It's simple -- the bloke is either fit to play or not fit to play, regardless of how optimistic his forecast was a few weeks ago. He obviously feels unable to play, for a similar reason that a couple of very high profile golfers have felt unable to play in big tournaments in recent months.
It happens. Australia will win the Ashes convincingly regardless of Trescothick's presence. It's so obvious that I really have no interest in the series this time around, or who's fit or not.
Sad but true.