I just did a quick search and found this as well!
Discovery of undersea creature leads to new archaeal phylum
By Kate Dalke
May 9, 2002
A new microbe has been discovered in an undersea hydrothermal vent off the coast of Iceland. The creature, named Nanoarchaeum equitans, is a member of the Archaea, the domain of life that is separate from plants, animals, and bacteria. The microbe does not fit any existing taxonomic groups, so the researchers who discovered it have proposed a new archaeal phylum called Nanoarchaeota, which stands for ‘dwarf archaea.’

Perhaps not terribly impressive, but it IS a new PHYLUM!
Read the rest of this article at GenomeNewsNetwork.org