There was a good, and amazingly civil, discussion yesterday in the comments to the Queue about which instance a tank should head to first. Most of the debate came about via my suggestion that Utgarde Pinnacle was a good candidate for a tank's first heroic. The nice thing about this game is that there is no right or wrong answer (most of the time).
However one of the only truths about the game is that you can get better at it by discussing it and debating the aspects of it with other people. So I do humbly recommend that no matter what question you ask, you always look for more than one answer and compile all the answers into one that fits you best. And with that said, ask your questions about the game in the comments and we'll see if we can't help you on this path of enlightenment. /zen
"I'm pretty sure that suggesting Utgarde Pinnacle for a new tank is the height of sadism."
In my opinion, not really. Utgarde Pinnacle has in it a few key aspects that all tanks should have quickly picked up. One is separating out mobs that need to die first and quickly. This is a skill that's learned early on: "kill the caster first!" is a common mantra. While there are some packs in Utgarde Pinnacle that might require someone with crowd control abilities, even those aren't too bad if the DPS focus fires down one caster after the other.
The only other thing about the trash is to pull the packs back to areas you've already cleared – which is a skill that should have been picked up in the regular 80 instances like Halls of Stone / Lightening.
The boss fights are all easy when the healer knows what he's doing. There are some positioning "gimmicks", like all grouping up for the final boss that are somewhat tank related, but it's nothing that is beyond any other heroic.
Finally, the only real challenge to the tank comes in the gauntlet. That's pretty easy compared to a speed run through CoT:Strat, which you'll notice I recommended a new tank start working on right away (albeit starting slowly). All a tank has to do is run down the gauntlet half way, stop, collect the mobs. After those are finished off, he runs down the rest of the way and does the same thing. The boss at the end of the gauntlet is tank and spank, sans moving away from him when he does his whirlwind of death.
And one last thing to note – I didn't say that a new tank should be brought to Heroic: UP. I said a tank that's followed the progression I outlined should be brought to Heroic: UP.
"Do companion pets significantly lag other players out while raiding?"
They can, depending on the person's computer. Additionally they can get in the way with click-targeting, which is something many successful DPSers do. And note that click-targeting means clicking the mob to target your DPS to instead of tab targeting to it. This allows the left hand to continue with DPS rotations via the keyboard and the right hand to control the target of the DPS via the mouse. It is quite a bit different from clicking DPS abilities.
"Also, is Patch 3.2 the definitive point for the next stage of the argent tournament? And if so could the new 5-man perhaps be inside the tournament?"
Patch 3.2 will definitely be progressing the argent tournament. We have no idea where the new 5-man instance will be.
"Sure running non-heroic dungeons is a good tip but really, who runs the normal level 80 dungeons?"
People who don't want to look or act like fools in heroic dungeons.