These suckers are big, like small-to-medium bacteria. The size of the genetic code base alone is astounding:
The discovery was just announced in the journal Science. That article is paywalled, but there's a nice pop article over at io9 and (of course/already) an article at Wikipedia.
These things raise a host of questions about the line between non-living and living. They can't reproduce on their own (non-living), but their complexity overlaps with that of eukaryotes. They have a primitive cell wall (sort of), but can't make their own proteins. And most of the genetic sequence is like nothing we've ever seen before. What the hell?
Reality is truly weirder than anything we could dream up.