Updated 6/18/09 at 8:15am: Push notification is now live.
The Associated Press was one company whose iPhone app was ready for Apple's software update to version 3.0 on Wednesday. AP Mobile 3.0 will now take advantage of the iPhone's new ability to push breaking news stories when the app is closed. When you boot it up for the first time, AP Mobile 3.0 asks if you'd like to activate push notification and then presents a list of feeds representing stories you'd like to be pinged about. International and domestic news, local news, entertainment, and sports stories are among them.
Integration with the multiplatform notetaking service Evernote (also updated for iPhone 3.0 today) is another change. In addition to posting AP headlines to Facebook and Twitter, you're now able to file them in your Evernote account, to reference from your Windows or Mac desktop, Web, or mobile phone.
Smooth scrolling, grayed-out headlines to indicate when you've read a story, and a few bug fixes round out the update.