I think a lot of people would agree me if I say elementaryOS has prooved to be ready for an office suite. Not only because of the length of the project and the support it has, but the wish of many people to see mockups like these become true.
I don't know if there are any plans to start working on these ideas -as far as I know, there was a fork of Abiword named Bouquin and nothing else...-, but these ideas are astounding and the system and environment have demonstrated they're rock solid for making this true as well. For example, we can have a look at Birdie, Daniel's mockup app for twitter, which was just made real.
I hope deep inside that all these mockups, all of them, became true. What does the devteam has to say?
Actually, I've seen yours, we even spoke in the comments about how more specific stuff would work. I really like your mockup, and how the secondary toolbar seems to change depending on whats selected. Maybe the main toolbar buttons could match between different office apps, like this Spreadsheet.