I tried it yesterday, and my first impression was "underwhelmed." I definitely don't feel that way about 3.2 as a whole, but the instance itself seems less than impressive, a one-room fight with almost as many boring moments as there are exciting ones. The fights themselves are actually pretty commonplace for a Heroic -- the jousting fight is probably the least-liked among the playerbase (seriously, whoever really loves the jousting mechanic over at Blizzard needs to take a good long look in the mirror for some self reflection), while the best is of course the Argent Confessor, who summons a random figure from our "past memories" to fight. I got Illidan and Onyxia the first few times I ran the instance, but of course Hogger and Van Cleef and Heigan the Unclean also have a chance at making an appearance. I did like the fight, but I was kind of bummed the old memories didn't bring any of their abilities with them -- they all have the same three abilities to throw at the group.
As for the lore, I'm torn. On the one hand, I did like that Blizzard mixed it up a bit, and tried to get us a little more involved in what the NPCs are doing than just having us go off on our own and take down a dungeon. On the other hand, that intro will be even longer the 25th time I'm doing it, and I'm still not convinced that messing around with an Argent Tournament is worth our time. One person dies in the whole instance (spoiler: it's the Black Knight, and he dies three times), and so while it was cool seeing our names shouted and being cheered on by the crowd, I can't help but think that it's still all just fun and games. When do we get to put somebody's eye out?