If one was to fully experience the game; complete the game on all difficulties, finish all side-quests, main quests, max out character, obtain all high level items, explore every inch of the map, etc. How many hours would it take?
 
I hate how people brag about finishing it quickly. I bet they throw the game aside afterwards, never touching it again.

Someone mentioned 40+ hours by doing all the quests which I assume would also involve all the maps and areas. So with power-leveling and loot, maybe another ten hours or so? I don't quite know since I don't have it so I wouldn't know how it works.

in the interview up on the site they said over 100

Well, I finished it on normal, doing 99% of the side quests and watching most of the character dialogue, and it took me just at 45 hours. On my second play through, skipping most of the dialogue and cut scenes, I think I can manage it all in less than 20 hours.
 
And you probably will not be able to "max out" the characters since there is no real grinding in the game. I was just at level 23 finish it with all but a couple of the mage tower quests done.

I hoped it would be at least as long as Baldurs Gate II with sidequests. Wishful thinking.

now did these speed runners take a nap at all? a pee break? that sounds REALLY fast to me

A podcast I listen too (I can't remember which...) someone mentioned that they've been playing for over 100 hours, trying to get absolutely everything they can on their first play through.

100 hours sounds like a bit of a stretch, I'm nearing the end at about 30 hours, and although I haven't done many of the sidequests, I don't think they would last me another 70 hours.
But I'd assume there's 10-20 hours left in the main quest and then another good few for finishing up everything else.. and I'm already looking forward to playing it again as a mage, rogue, elf and dwarf.  So the length certainly isn't anything to scoff at, there's a lot of replayabilty.

Dave said 45-50 hours roughly, pending your class, route, difficulty and experience it will be around that time.

I'm 30 hours in and I've only recruited 2 factions(of 4?) and barely touched the side quests. Depending on if you actually play the game rather then blow through it so you can brag on a message board the game will last you quite a long time.

ALL difficulties? Yeah 250+ hours. Just Hard and Nightmare? Maybe 150 hours, if you breezed through Hard and took your time fnishing up all the random little stuff on Nightmare.
 
To complete all quests and all tasks on all difficulties, that's a time investment that borders on obsessive. Nothing wrong with that, but just like I eventually sunk 300 hours into Oblivion, DA:O would take a LOT of time to fully explore in that way.

I don't know. I've been playing for probably close to 40 hours now, and I don't think I'm anywhere near finishing. I've been doing a lot of side quests, and lengthy conversations. I tend to take a while with games though. I guess I'm just slow.

There's also supposedly no level cap, so maxing out your character is pretty much impossible.

" @PureRok: I'm sure you can max out the talent and skill trees and put all stats to, possibly, 99. That said, that would take a helluva lot of time and would be highly unnecessary.  "

I like to see everything in a game my first play through. I played the main campaign in 55 hours. Granted, that included 2 or 3, one-hour long breaks or so, but yeah, it is a beefy game. I also spent around 1 hour on each of the subsequent, "Origin stories" of which there are 5 more after the initial one. It is well worth it, and I am really interested in seeing how some of the factions treat me now that I am a different race. It definitely is going to play completely different. There also seem to be about 4-6 different endings as well. Great game and well worth full retail price. You get free DLC in the retail box for an NPC, and a suit of armor that you can use in Mass Effect and Dragon Age.

It took me 53 hours to complete first time. Normal difficulty mind you. I did the majority of the sidequests.

Doing the majority of it the side quests, it took me roughly 70 hours to complete while playing on normal.

I was in the 40-50 range in terms of 'played time', though I reckon this doesn't factor in deaths and retries and the odd crash that I had to play through (though I suppose that's cheating).  I got the 75% of sidequests completed achievement and I chatted up all the companions and did the DLC content, all on normal.  I'm not sure how others exceeded this time, unless it was through some serious backtracking to pick up every last thing, for example, running through dungeons a second time in order to pick locks, stuff like that.   
 
By the way, if you want to grind, you can do the unofficial provings in Orzammar.  You get peanuts in terms of cash, though, and no equipment.

I've only done two factions and I'm a little over 20 hours in. I've started doing some more side quests too. I also love dialogue so I talk to a lot of the characters a lot. I also, seem to play games slower than some. But with all that being said, I would guess that its probably around 40-50ish hours. I think Dave said it took him just over 50 hours to complete his first playthrough and that was just doing side quests that were pretty much on the way though the main quest.

Completed 3 factions, working on the 4th, all DLC complete and a good chunk of the side quests complete and I'm clocking in at 50 hours right now (Hard).

" ALL difficulties? Yeah 250+ hours. Just Hard and Nightmare? Maybe 150 hours, if you breezed through Hard and took your time fnishing up all the random little stuff on Nightmare.  To complete all quests and all tasks on all difficulties, that's a time investment that borders on obsessive. Nothing wrong with that, but just like I eventually sunk 300 hours into Oblivion, DA:O would take a LOT of time to fully explore in that way. "