iPhone Developers were displayed a message that shows that Apple has completed its iPhone push notification testing.
MacRumors has posted an image which thanks developers for their help and feedback and informs them that testing has completed.
Two weeks ago Apple asked developers actively working with iPhone OS 3.0 beta to help in testing the Apple Push Notification service. They selected a pre-release version of the Associated Press app for iPhone OS 3.0 to create a high-volume test environment for the push notification servers.
This news along with the release of iTunes 8.2 indicates a strong likelihood that WWDC will see the release of iPhone OS 3.0.
Update 1:
Push Doctor is the new best Push Notification Solution: