An interesting article at businessinsider.com regarding how App prices will be set for the Kindle. Apparently the developer can set the MSRP (Manufacturer's Suggested Retail Price), but ultimately Amazon gets to set the actual sales prices. The developer gets either 70% of the actual sales price or 20% of the MSRP -- whichever is higher.
Apparently developers aren't quite sure how they feel about this.
Personally, I'd just like to get access to Amazon's KDK (i.e. SDK).