Interesting finding, but one which should be taken with a grain of salt.
From what I've read at various sources, there may be natural, non-life explanations for what is being observed. Photochemistry, cold-temperature chemistry, etc.
Even if those alternate possibilities don't pan out, it isn't proof positive for life, although it would be evidence in favor.
I think the possibility of non-earth life in our solar system is quite high - we know of several moons with liquid water, allowing for the possibility of earth-like life. Plus there are cases like titan where there is the possibility of life unlike anything we have here.
But while I'm optimistic, I think we need to be prudent - life should be the last explanation we apply to observations like these, and even then, should only be put forth as a tentative conclusion.
As for the OP's original question, I think we'd have no trouble identifying it as life. While there isn't a set definition for what constitutes life that is accepted by all biologists, finding something that is a self-maintaining chemical system that responds to the environment, reproduces, has inheritance, and undergoes some type of evolution, we'd have proof-positive of life - even if chemically it didn't look anything like life here on earth.
Bryan
