Amadinejad says he doesn't fear a US invasion. Hussien didn't, either.
A couple of things of note in that article. Not only are the Iranian leaders insane if they think the US won't invade, and won't wipe them out, because, of course, they will. However, they are wise to note that due to being mislead about Iraq, Congress and the public won't let this (or any other) administration attack another country without a metric assload of proof.
Which is yet one more little bit of damage done by this Administration by attacking Iraq. Not only are resources tied up that could be used to attack/defend against a legitimate enemy (and Iran very well may be), but when they try it, no one is going to believe them.