I have been playing with iOS5 for a while and thought I'd give a brief impression of what you have to look forward to when it is released later in the year.
I'm only going to briefly give an overview. Maybe later I will go into more technical detail but for now I thought I'd just talk from an every person perspective.
The usability of iOS5 is good. The first thing I have enjoyed working with is 'Notifications'. This feels more like android but even in the beta runs very smoothly. You simply swipe down or up to display or hide the notifications screen. This is great because notifications don't interrupt what you were doing when the message or reminder came through. I also like that you can sort notifications by either the time it arrives or you can reorder the apps individually. You can swipe right to go directly to the source of the notification although at least in the beta I find this has a little lag, hopefully this will be better in the final release.
The feature I love the most at the moment is sync. If the phone is syncing you can still use it. That's a great benefit. In iOS4 once it started syncing you basically had to leave it until it was finished and we all know that can be a lengthy process.
iMessage is another great feature. The ability to send anything to anyone with an iOS5 device and not use any network is awesome. It integrates into the message app well and automatically detects whether the person at the other end is using iOS5 so there's no separate app and it works well. You can even have a conversation with someone over iMessage and see when they are typing.
I am currently utilising sync over iCloud and am still working through this, but it does appear to be a nice seamless feature.
There are a lot of awesome features in iOS5 and I think as I get used to it the full benefits will be realised. It is definitely something to be excited about. I will continue to work with it and the rest of the features to see how it all works but at this point although there is nothing earth shattering, I am excited and can see the benefits and think it's definitely something to be excited about.