WRONG!!!
You do not need a bed to level up, but you choose when to level up. Todd Howard himself stated that you can choose when to level up and it will act like a "super potion" that will immeadiatly fill up your health, magicka, and stamina bars.
This brings other questions to attention:
(1) Will our skills stop improving until we choose to Level Up?
(2) Will we be able to "hoard" multiple level ups?
(3) Will clicking the Level up, if pt. 2 is true, level us up ALL those levels or just 1 per click?