Yes it has been. It was confirmed at an event in Europe about a month ago.
Well I sure will try it without sleep, probably during a weekend. Going to be a challange for sure :-).
Dude your not meant to do the whole 24h alone lol.
I hope they have implemented like a system where your teamates are on standby and are alerted so when you go in the pits they take over.
It would be cool if you could save it after your stint is over and then send them the save file so they can start from where you left off. That would be a lot easier than sitting there waiting for your friend to finish. Then when you are done a third friend takes over And you leave and while you're gone his mom tells him to get off the ps3 or somesuch and he just quits the race and throws in the towel.