TF2 definitely has a higher skill ceiling. None of the characters in Overwatch can move like a good Solider or Demoman can in TF2 (I'm guessing it's just not possible to do stuff like Rocket Jumps/Sticky Jumps well with a controller).
From my time playing the Overwatch beta if you go up against 2 players by yourself in Overwatch it seems much less winnable then a 2 on 1 fight in TF2 does.
In TF2 the closest thing to an Ultimate is the medic's ubercharge, which a medic will loose if you kill them before they deploy it. In Overwatch if you die while you have ultimate you don't get penalized. You also have no way of knowing when a character has their ultimate, while in TF2 you get little hints when a medic has their uber (they say a line and small amounts of lighting/electricity starts appearing on the medic's medigun).
Yeah this is basically what I meant. There are a select few overwatch heroes that have the same "skill ceilings" as TF2 characters (widow, genji, arguably mccree and junkrat), but the rest require little to no aim or movement ability - its just positioning and decision making, almost like Dota.
Its pretty clear if you look at the TF2 class analogues in overwatch
*Widowmaker has an escape (grapple), very good close range damage, and a high HP pool. Sniper has no escape, low HP, and only the absolute best players can use him effectively close range with quickscoping.
*TF2 Soldier takes hundreds of hours of practice to effectively move around the map using rocket jumps. Pharah has you press shift
*Tracer reduces the speed of scout, gives her more dodges, and even gets a "get out of jail free" card whenever she's in trouble.
Overwatch is just a lot more forgiving of mistakes, even on its high skill classes. This isn't to shit on overwatch - I think its a really fun game. I just don't know if I see myself playing it 50 hours from now. I certainly don't see it becoming a big esport or anything like that.