May just be my imagination, but sometime I notice shadows that fly across my screen.

I look up, and there is nothing there.

My only gripe is that there are NPCs that will 2-3 shot me on normal difficulty. Dragons are fairly easy since they only breath once or twice, then fly away for a few moments.

I've encountered three dragons thus far (currently level 12). The first was everyone's first. The second was just outside Whiterun and it just circled overhead without hostility... eventually going away. The third attacked me as I was leaving a dungeon at night. I managed to kill the third, but only because the dungeon had a bit of exterior architecture I could hide and heal under when needed... only to come back out, sporadically, and whittle away at the dragon's health. The music is awesome... but I don't think I'd stand a chance against one of the beasts without such cover. Fortunately, I had it for that time.

The one random dragon I fought was pretty easy, but that's probably because there are different types of dragons and this was the easiest one.

too bad they dont apear unless you start the main story, i was planning to not be a dragonborn but it was no fun without the dragons so im now dragonborn

I was in solitude and heared a roar, a dragon came and circled the town and just flew away, shows how well they have been done

I was lucky to encounter two at lvl 7, the first went down fast, but I struggled with the second. With the first I could actually see my swords hack off heaps of the dragons HP (died in mere 10 seconds) where as with the second I could hardly see the HP go down and I actually had to flee.

Today I was fighting a dragon from atop two towers with a bridge over a large river (somewhere between Whiterun and Windhelm holds.) I didn't kill the dragon (it flew away after I hit it with a few Fireballs) but it was cool to watch the dragon fly around the towers from such an epic view.