More specifically, if you receive more than one notification, the former is pretty much lost. Your app icon is annotated with a number but you have no idea what happened if you have several icons already annotated.
Thanks, that's a good point.
I haven't been following the evolution iPhone OS releases during the beta phase, but isn't it possible that features are added (or removed) before the final release this summer?
It's possible, but Apple generally only adds small features after the initial introduction of a new system. I would be extremely surprised if something like notifications received a total overhaul for the final version of 4.0; I think they would have mentioned that.