Sorry to resurrect this old thread, but I was looking for the answer to this exact question: is the MacBook Pro's 85W MacSafe power adapter compatible with the new MacBook? Well, it certainly seems it is.
To the people thinking that the MacBook's power adapter is compatible with the MacBook Pro: it both is and isn't. You can charge a MacBook Pro with it, but when it's battery has completely run out of juice, the 45W or 60W power adapter won't have enough charge to 'kick start' it back into life. Well, at least that's what I learned from reading, in search of the answer to my question concerning the MacSafe adapters. Some people even say the low wattage MacBook adapters won't charge a MacBook Pro unless it's sleeping. The bricks will keep the MacBook Pro's battery at level, but won't actually charge it when it's in use. Can't confirm this myself, so don't know if it's really true, though.
But thanks (again), Mac Rumors. Whatever question you have, the Mac Rumors people will find the answer.