Extended Rest does indeed recover PCs to 100% - HPs and surges combined. Keep in mind tho' that healing in most every form (including the vast majority of cleric/warlord/paladin healing powers) use up surges, so surges are ultimately your only way to recover (once you're out, even a cleric isn't of alot of help, unless he has a power where he can use one of his on you).
Diseases do extend past encounters, and are way more dangerous than their 3E counterparts, but thats about the only thing that comes to mind. Bleeding chars of resources 3E-style does still work to an extent: if you force them to use surges, you are depleting them, even if they don't use any daily powers or the like.