Notification wise, I wasn't real thrilled with how Android handled it when I did my evaluation last summer. It was different then iOS for sure, but it had it's own mixed bag of pros and cons. While I haven't personally used a WebOS device outside a store demo, their approach seems to be a bit better then the Android method. Coming in from the bottom, resizing the app if needed, and giving a better at a glance view, without being the modal dialog iOS uses.

I also didn't enjoy having to play notification janitor on Android either. Though that is probably more due to bad use by the developers, including the stock Mail app not clearing new mail notifications if they were read on another system, and Gowalla using a pull system vs push.