Well, after 3+ years, 75000 kms, and 30 track days, I've had my second failure - clutch thrust bearing seized. (First failure was a cracked header, which I had welded up 6 mths ago, and it's still OK)
I have no idea why the thrust bearing failed, but I'd resigned myself to probably also replacing clutch plate and pressure plate while it was out. The good news is that my clutch plate and pressure plate look great, and they're going back as is.
Recently someone said that you have to upgrade clutch if you go FI - this is proof that you don't. I believe that the real clutch killers are drag racing and gymkhanas - which I don't do.