If we have the old version, will we only need the new rules to make out set "second edition?" or will we have to buy the whole new game?  Will you post the new rules online?

FFG will for sure provide the rules online in given time.

I'm hoping for new cards but fear the same as you - it  would mean to buy the new copy. Let's wait and see.

Well the answer to those questions is simple, I wondered about it in the comments section of the announcement and got this response: 

There are no changes to the rules or cards of the game. The box is smaller (the size of the new "Hey That's my Fish" box).

Christian
  FFG

So there will be no difference in content, 1ed and 2ed are the same when it comes to cards and rules. If you own the 1ed then you don't need to buy 2ed.

I've pondered this game fofr a while. Now that it wil be $12 I won't be able to resist.

Thanks FFG

 Judging by the pictures of the tokens and score cards what has changed from the 1st ed. which I have, is that tokens that were used for scoring are cardboard and marked with the respective agency shields. Mine are blue and red glass beads, and the Balance, CIA, and KGB tokens are also cardboard and not poker chips.