The first thing to address: Are these two devices truly competitors? The answer is yes - but only to consumers who don't know what they REALLY want. You see - Both are extremely portable 800x480 Internet centric Linux devices in the $400-$470 street price range. However, both have clear cut advantages in certain areas that would only be of benefit to people who knew those advantages beforehand and used them as a basis for a purchasing decision.
http://www.ultramobilegeek.com/2007/11/asus-eee-701-vs-nokia-n810-linux-fight.html