You ask what people would want to see differant and your going to get a hundred differant contridictory answers. For example I think the game needs to be even more RPG-like IMO and totally disagree with the idea of making combat "FPS-like". The issue with missing people with 100 skill is because opponents level up with you and when you have 100 skill so do they, which is.... one of the bits I admittedly don't like.
I also think a less trivial storyline would be a bad move simply because they tried that with Daggerfall, and truthfully it ruined your abillity to wander around and do whatever you want since it was so easy to miss the main quest or a timed meeting.
Personally I would say the following:
#1: I agree that they should open things up a bit more to let you explore more than one region of the world at a time. Arena and Daggerfall had the entire world open pretty much, Morrowwind and Oblivion were a bit of a let down with only one region (no matter how full).
#2: The game needs more factions/guilds to advance in. Every game we see less and less guilds since Daggerfall. I find it annoying.
#3: The game needs more skills and such, I think Oblivion dumbed things down from Morrowwind and Daggerfall WAY too much.
#4: Set enemy levels, or at least within a range in each region. I do not care for the idea of enemies leveling up whenever I do, so there is little sense of progress unless I use unlikely skill combinations to prevent myself from leveling up beyond a certain point.
#5: Less lazy game designers. No offense but one of the biggest things that annoyed me about Oblviion was recycling a lot of the books and such from Morrowwind. All the work that went into such things was one of the things that made Morrowwind.
#6: A continuation of the above, these games have always needed a MUCH larger bestiary. There just aren't that many kinds of monsters.
#7: A new magic/racial system. Simply put one thing I do not like is that since Magic is such a huge part of the game, it favors a couple of differant races (Bretons and High Elves) due to their magika abillities. I would like to see a system where you could build a power-mage without nessicarly being pigeonholed into one of the races with that advantage.
#8: Bring back the REAL Redguards please, it isn't high fantasy without Dwarves. Plus honestly once Orcs became playable I see no real need for another purely martial race.
#9: I doubt anyone from Bethesda would have read beyond #5 and #6 (curse my silver tongue) but I REALLY want them to do something with the Sload. I mean we've been hearing about the ancient Sload empire for ages. Other than whacking them occasionally for yucks or to get soap we've never seen any real follow through other than like "Shadow Over Hackdirt".
Let's explore some Sload ruins!
Just imagine the plot: A return of a Sload empire causes them to rise up from the depths to overrun the biggest naval power in Tamriel (Hammerfell) nuking the Reguards to near annihilation and forcing them into chains. Thier invasion however upsets some dwarven technology (a switch noone was left to push) which causes the Dwarves to re-appear from the ether they accidently banished themselves to in their ruins to go to war with the Sload to reclaim Hammerfell.
You can free the enslaved Redguards and help resolve an issue of where they live now since the Dwarves have reclaimed their lands, fight the sload, play a Dwarf with a good solid two handed battle axe, a mining pick (we need mining skill!), smiths hammer (we need a weapon forging skill!), pet clockworks, and a Beer-helmet with two mini-kegs attached to the side.
Yes we need Dwarves.