I believe this is excerpt is accurate:
"More importantly, IZOD will be contributing to the IRL's Team Enhancement Allocation Matrix (TEAM) funds, guaranteeing full-time IndyCar teams an annual boost of over $1.3 million per year."
That came from the following post, which could be confirmed at the IICS website if their news archives worked like they used to. Oh well...
http://motorsportsforum.com/smf/index.php?topic=13324.0
The Izod bounce to that total per team is said to be a small one. Keeping that $20M plus in the IRL coffers is pretty close to the amount they need to put the Series books in the black.
Yes, there is addtional prize money paid for P1-P5. The figures are buried somewhere.