It's already been said, but an improved notification system and photo folder options are my two biggest wishes for IOS 5. I could really care less about wireless syncing because it is an necessary drain of battery. Is it really a big deal to just plug in your device to the computer? I'm on my laptop all day, so it's not like that's out of my way. A live weather icon would be nice, but really any other types of widgets are absolutely useless to me. Personally I just see widgets as a gimmick and battery drain (in case you couldn't tell, I like squeezing out the most battery I can from my device 😀 ). If my device responds quickly, I don't mind having to launch an app to check the news or whatever. But weather is something I check multiple times a day, so having that in a widget style is useful to me. But everyone has different needs, and this setup works fine for me.
The whole mystery and lack of info about what will be in IOS 5 just makes me even more excited for the preview at WWDC!