Ok, I know it's not official, but I was looking through This Document and it says

An extended rest is akin to “camping” and lasts 6 hours. After an extended rest, you’re fully healed, you have a full compliment of healing surges, you have your daily powers back, and you reset your action points to 1. You can take an extended rest once a day.
WTF!?

If I read this right, then a character can take no lasting damage. A full day of being battered to bits, ripped to shreds, having possibly been down to negative hit points, and possibly (if no cleric is available) a hasty heal check to work out which way round his kidneys go, and he gets up the next morning as if nothing has happened.

I repeat...

W...T.....F?!!???