• We have updated our Community Code of Conduct. Please read through the new rules for the forum that are an integral part of Paradox Interactive’s User Agreement.
Don't worry.

It will be sold at Steam, but also at other digital distribution websites like Impulse, Gamersgate and Direct2Drive (and of course retail). And these versions will not use Steam.

So there is a lot of choice.
 
This is true, I can confirm I bought Empire Total War from Amazon.com and it REQUIRED me to install steam and would ONLY Install via Steam. So retail games can require steam. This happened to me with Dark Messiah of Might and Magic as well, I bought it from Amazon.com and it would only install and work with Steam.