OUCH! Sorry to hear that! Face it, dead is dead, but it's in the dying that tells... asleep in traffic or Rock n Rollin' out of some chicane... well done! How many guys can brag they blew up a Porsche?... On the Track??
Not likely a slipped sleeve, haven't heard of one of those reported for years (probably all washed out of the fleet by now) and NEVER beyond 25k mi.
That's become sort of an urban myth, one that's likely hurting sales of early cars. Relatively few of these cars were produced and fewer still made it into the US market. Unlike the revised IMS which is ticking away in
every later model Boxster. Personally I like my chances of a sleeve issue waaay more than if I had one of those self-destructing intermediate shafts.
Keep us posted on the transplant patient!