Larisa has a few more: Children of Wrath will never have to go back and do old instances just for the achievement, or have to decide between keeping that noncombat pet or getting the extra bag space back. She was actually a "BC baby," and as she says, she's never tried to run 40 people through Molten Core, or known a time when there weren't any quest chains in Silithus.
What else will the children of Wrath have missed out on? And are there really that many? I imagine that there are still quite a few vanilla players around, and it doesn't surprise me at all that there are plenty of BC babies (I recruited a few people during BC), but how many new players are really coming in to Wrath for the first time? Are there going to be that many people who don't remember when you had to run once instance over and over for rep, rather than just champion it?