@Bharath - I also like MP6 and have been using it ever since I discovered it.

@Tung - I didn't think tabs were the answer but it's the first things I thought of when trying to improve my own experience with the Post creation screen. I like the UI concepts much better than tabs. You may be right about establishing new, better content creation habits but I think the new Post Creation screen UI addresses this a little bit by rearranging things.

@Jon Brown - It wasn't clear to me on whether those big icons were actually dedicated to Post Formats or were merely used as a way to put a certain type of content into a post. If it's for Post Formats, that's a large chunk of real estate wasted for me. If it's for building content, then maybe not so bad.

Wouldn't just making everything in the back-end of WordPress responsive address your mobile concerns?