I am curious about a 24 hour track race for the pure simplicity of it but not for me at the moment. Never say never though.
Yep that has been me for several years now curious and I somhow think overcoming the mental challenge would be immensley satisfying but what worries me is the potential damge that the constant rythm may do to my body over 24 hrs.
This is an intriguing question FR. My query would be how does it compare to say the lakeland 100 or other - for most people - 24hr+ hilly trail events? I know there are a few pretty good 24h track runners at my club (past and present), but I've only really talked to one of them and he never has really done a very long ultra trail so can't really answer. I know the other guy does a few ultra trails, but doesn't train with club much so rarely see him to pose the question - will if I do.
I can imagine the constant rythm could hurt or damage, but like other forms of extreme endurance is it going to go unnoticed until later? There isn't the exertional force of downhilling like on the trails, but the trails offer a variety of surfaces and grades of hill and flat to work a variety of muscles and somewhat even out the "battering" I suppose. The RR50 on Saturday hurt a lot less the next day (barring knee) than HM60, which may just be explained by 13 less miles and many hours less on feet. In turn HM60 hurt less than 50 mile I did of TDS - but this is just how much it hurt during, after and how long I took to recover.... which does the more damage long term I'm not sure how you'd find out 
e.g. an extreme example but.... the theory amongst Tour de France competitors that the effort of a tour takes a year off your life, a tour that leaves you wrecked and a in a bad way a few years. Like I say an extreme example I know and I know were not talking about premature death here really, but thought it worth mentioning.