Crossbow are not in the game.
best - revampled level scaling
best - it's in skyrim... actually this should be at the top of the list
best - hand crafted world and dungeons. this gives me great hope that it will have atmosphere like MW. (see worst on leveled loot that knocks it down between OB and MW for atmosphere)
possible best - dragon behaviors. would love to see a random dragon attacking a town
worst - leveled loot. this was talked about in some magazines.... what is the point of dungeon crawling if the loot is based on your level. add some danger and surprise and go for some actual imaginitive thought
possible worst - "side job system" - If it is like fable 2 then we are seeing the beginning of the end of Beth as a great developer. If not it really needs depth to it besides just supporting the crafting system.
likely worst - loss of spellmaking - I never really used it myself. But if your going to take out a well loved feature and replace it with a crafting system that could break balance just us much as spell creation you should at least try to put it in.
likely worst - skill tree/perk combo system - Since it is confirmed that we can "rank up" most of the perks multiple times under each skill I have the feeling the system is going to be terribly generic and boring. I.E. +5% firebolt damage
I think skyrim is gonna be great but I hope Todd isn't going all Molyneux on us with the "streamlining" and "mainstreaming" just to reach a wider audience