Yup, I take one with me every time I travel. You do need to configure it at home before you leave but you only need to do it once, after that you just need to plug it in. Unless you have iOS 5, then you can configure it from your iPad.
It's very unlikely the iPad will ever get an ethernet port, it's just not possible considering how thin it is. I think the AirPort Express is a great solution though, I love mine.
Interesting. So iOS 5 provides the ability to configure an Airport Express directly from an iPad? Outstanding. Really no need to bring a laptop then.