The Paradox Forums have details on how they will be offering the preorder bonuses for Europa Universalis IV after the release of the upcoming strategy sequel on August 13th. They also announce a new preorder incentive for those who preorder the Digital Extreme Edition via Uplay will get all the previously revealed bonuses plus a copy of Splinter Cell: Double Agent. Word is they will be offering the various preorder incentives as DLC on day one, including the utility to convert Crusader Kings II saved games for Europa Universalis IV, which will be $9.99. Here's the rundown:

Europa Universalis IV: Digital Extreme Upgrade - $7.99
Stars and Crescent Pack
Horsemen of the Crescent Unit Pack
Conquest of Constantinople Music Pack

Europa Univesalis IV: Pre-order DLC Pack - $6.99
100 Years War Unit Pack
The Purple Phoenix Expansion

Europa Universalis IV: Call to Arms Pack - $3.99
Winged Hussars Pack
National Monuments Pack

Crusader Kings II: Europa Universalis IV converter - $9.99
* copy of Crusader Kings II base game is not included