I've been looking at TV by the Numbers, and they have it about 50/50 on the renew/cancel index.

I know everyone is comparing it to Mr and Mrs Smith, but the premise reminds me of the '80s drama Hart to Hart. I mean that as a compliment.
Then you are winner, because that's what the show was inspired by! (I should probably try to see some of it, since I seem to have a thing for spy couples...)