I'm always amazed by how quickly people demand nerfs around here. I picked Irelia up as a top lane after trying her during her free week and I'd maintain that she's not OP. She's good, but as another poster said, she doesn't have dominant damage or CC. Her sustain can probably give some players fits, but even that isn't going to ruin the game.
I always end up wondering if the people like the OP here just ran into a champ that beat them hard and they are using this forum to try to remove the champ they couldn't defeat. Honestly, there are at least 4 other top laners I fear more than Irelia.
Can't speak on the nerf pattern though. I've had people tell me that she got hit with a nerf bat in 7 straight patches at some point, but I have no way to confirm that.