I've spent far more time playing Skyrim than I have Diablo 3. It's probably not a game you want to get if you are just looking for a "change of pace" from Diablo as you can spend countless hours questing, exploring etc. in Skyrim. Skyrim is truly a game of infinite length with never ending quest lines. The gameplay itself is certainly different from Diablo, as is the leveling and skill system. Skyrim is a very fun, engrossing game, with a good story line but if you pick it up just to play for an hour or two once in a while, you definitely won't be getting the full experience.
I do not agree with this statement. Or, at least, while I guess it is technically true, I disagree with the intent behind making it.
I pre-ordered Skyrim and was done with it before any of the expansions came out, so maybe that was the issue I had (also didn't do much with the modding community). He is correct in a sense that you can make up content to do for forever in the game if you please, just like in D3. But just like in D3, you reach a point where you can no longer progress.
I "finished" Skyrim in around 160 hours I think (I would have to check my steam account at home). By "finished" I mean I maxed every skill, had completed every major story line, had found all the dragon words, all the ancient artifacts, had bought and furbished all the houses, had over a million gold (which was pointless, but it still took a while just being able to sell all that stuff, heh). I spent a fair amount of time leveling skills I never used and wasn't specced into just to be able to say that I maxed all of them. It actually made it somewhat challenging, too (when I finally switched back to using gear I was specced into I was basically invincible).
Once I reached a point where I couldn't progress my character, I stopped playing. I could have started a second character and gone with a different play style (mage type), but I would have been doing the same exact things, simply in a different way. I decided it wasn't worth it and moved on.
It was still very entertaining for the time that I played it, I'd highly recommend it (I did play on the PC though).
I also played both Dragon Age games and enjoyed both of them, though I recall replaying DA1 more than DA2. If you enjoy those types of games though, no reason not to pick one up.
edit: HA! Facebook status update from March 4, 2012:
just maxed the last of my skills in skyrim, booyah!
what to do now until diablo 3 comes out ... reroll as a mage type? go back to league of legends? find a new game?
decisions, decisions ..."