Is Plaxo a Threat To Facebook?

Since yesterday there has been a significant amount of buzz surrounding Plaxo’s new social network, Pulse, that they are launching on Monday. The new network provides users with extended features that allow them to differentiate between contacts that are friends, family and business contacts. This is a feature that a number of people have been calling for (myself included) on Facebook. While at the current time there is no such offering within Facebook, with a little bit of programming, a new application could be created that adds these features.