Eris

New Planet
Information about the object, its discovery, its place in the solar system and ongoing research, by its discoverer, Michael Brown.
http://www.gps.caltech.edu/~mbrown/planetlila/

The Tenth Planet
An ongoing series of articles in weblog format about the discovery and classification of the object unoficially called Xena.
http://www.tenthplanet.info/

Wikipedia - Eris (Dwarf Planet)
Article describes the discovery and characteristics of the object and its place in the solar system.
http://en.wikipedia.org/wiki/Eris_%28dwarf_planet%29