If these things haven’t evolved into anything more than some one celled organisms in that amount of time, I don’t see what the huge deal is.

Well, consider some of the assumptions built into your sentence. I’ll just ask some questions that I think might be pertinent, assuming that the hypothesis will be confirmed by more study and/or future Mars missions:

  • Why would you expect these organisms to evolve?

  • Given the limitations imposed by environmental conditions on the complexity of life on Mars, what can we learn about the interrelationship between organism and environment?

  • How is the discovery of an extraterrestrial life form not a “huge deal?”

  • How did the organisms get there in the first place?

  • What is God up to in either directly or indirectly creating life in other places besides Earth?

  • If you’re a theist, does this discovery not constitute evidence for theistic evolution?

    • Now, excuse me while I change my Depends…