I'm a huge fan of the "CRM for everyone" direction, and love the new UI, and it would seem it is tailor-made for re-thinking e-mail integration. Would love to see one of two things happen:
1) Bring Salesinbox into the proper UI so that you don't lose the whole UI context when you launch it. The current implementation just makes it work like a new, inferior email client as it doesn't feel integrated at all.
2) Bring Zoho Mail into CRM. This would be my preferred option as I love Mail and it already has some great CRM integrations. I think every other CRM would kill to have a native email integration so I don't know why you guys force us to switch between two apps, when it would seem like a simple iframe integration! Every sales person I know lives in two apps - email and CRM, so it would make like so much easier to have them in the same UI.