@JoshRoss:I agree, wp7 is a great product as it stand now. That said my understanding is that Apollo will add value by providing a common base / closer integreation with Windows 8.
NB From the wp devcon (October):
"This session will guide you on how to develop for Windows Phone Apollo, the new version of Windows Phone due out by the end of this year. You will learn the new resolutions needed to support and target Windows Phone Apollo, the new hardware you will program against, the changes coming to the Windows Phone Marketplace, and much more. There will be some code shown, which will help you migrate your Windows Phone Mango apps to target Windows Phone Apollo. The session will also help you understand the marketing aspects of apps targeting Windows Phone Apollo in order to help you get your apps approved the first time. You will also learn about the new emulator as well as new reporting features available in the Windows Phone Marketplace.
At the end of the session, you will be ready to write and upload apps to the new Windows Phone Marketplace. Please note: Knowledge of the Windows Phone Developer ecosystem is required. In order to appreciate the difference between Mango and Apollo, it is also preferable that you have developed at least one app currently in the Marketplace."