Yes, guns bad. Very very bad. Spoil game. Go play Halo if you like guns.
Boats sound intriguing though, especially if acquiring your own boat takes a little while, but allows passage to otherwise unreachable islands, areas etc. Approve.
Big improvement area is to make combat and magic more dynamic and exciting. Melee combat should start to feel more like 3d fighting a la Tekken or Soul Blade - ish, with proper technique, tactics, and special moves; where skill, as much as on-paper stats, counts in disabling one or multiple enemies. To do that, combat needs to be a bit more complex, where there are more varied reactions to different real-time situations and techniques. Combos, stuns, knockdowns, wide area attacks, etc. Don't like standing there hacking away at an enemy's head whilst he stands there and does the same to you. That's not reactive enough, the first person to be struck should recoil accordingly. Plus much more methods for effectively dealing with multiple opponents.
Same with magic. Hit someone with a fireball or lightning and - poof - little spark, but they keep running towards you like nothing happened, even at high level. See? Too unreactive, too pedestrian. Needs to be more exciting. Fire spells should explode sending people flying, ice should freeze them solid, lightning should stun, etc etc. This adds much more scope and possibilities for fighting.
Maybe I dream here, but option to blend multiple elements into new, more powerful hybrid element? Blend fire and poison to make new exploding gas bomb thing. That's just me indulging myself.
Everything else about Oblivion awesome though. Still my fave game ever.
AND GET JEREMY SOULE TO DO SOUNDTRACK. He's an awesome composer - and please release your soundtracks on CD. Most annoying having to do digital mp3 download, I want a proper box copy.
I think most of us came to the conclusion guns are not needed in TES thanks to magick.
Lets discuss something else like: Boats!
Yes we need boats, and the ability to own your own one.