I am running Skyrim on the highest possible settings, at a constant 60 fps... but I get an ocasional popup in the distance... and sometimes as close as a hundred feet or less..

Is this normal?

Specs
i7 2600k
SSD
7970

Popup? Like a windows popup, steam popup, what?

I'm thinking he means pop-in like the mountains popping into view, or trees maybe.

I'm not playing on highest settings, but it seems that this game is killing the best systems.

Yes there will always be pop-ups, because Bethesda uses a pretty bad LOD system. That's normal for Bethesda's games, that are recognized to have bad technology nowadays.

Other games (for instance Crysis, I think) have 5-6 different versions of LOD details that STREAM in seamlessly and faintly, not like a massive pop-up.

Yep happens here

Yep, however their streaming is much better than oblivion, definitely an improvement. Not as seamless as Just Cause 2, but oh well