Are the new raids too easy?

That's been the claim so far. Tigole has responded in the forums though with the following...

We expect Naxx to be the easiest raid dungeon in WotLK. If experienced Sunwell guilds were repeatedly wiping, the dungeon would be overtuned.

The raid game will ramp up over time. There will be many extremely difficult encounters for people to face. But the early bosses in Naxx are intended to be beatable very early on.