Just thought I'd speak my mind here for a second.
1. I think that Away players should be displayed before the Mobile players. It makes it very easy to miss if one of your friends is online, but just away. Or at least give us an option to hide Mobile users.
2. I'd like to have the option to start a new conversation with someone during champion select. It's awkward not being able to talk to my friends unless they whisper me first.
I also personally don't like the new chat box system. I much preferred multiple tabs at the bottom but I understand why you made the change.
Overall I love the new client, but there are just a couple things i'd like to see changed. Keep up the great work!