I haven't found myself missing my N9 except say I think it's the perfect size. However, The 920 is faster, very smooth OS as expected, the browser is quite nice, camera is great.

Email wise, the both work... a bit better on 920 now that they broke notification for IMAP on N9.

I miss some things on my N9 like the feed screen but a lot of that was populated by apps. I miss the swiping everywhere, double tap multi task control, but they aren't killer things.

I could see a super live tile created to help with the feed screen. OTB tiles only have like one item showing for emails and calendar. Useless.... there are apps for that so it can be done but it should be OTB.

I would like the option to install other internet browsers if allowed but I'm not sure all the rules for WP8.

Anyways, I do look forward for whats to come in WP8 and will be checking to see how the community here improves the N9