NO way in hell Bonaire will hit 400 MH/s... 360 is a possibility and that's with the noted 7.4% increase due to arch and pushing the core to 1300.
Yea, once AMD releases new drivers and OpenCL stuff that targets the improvements in the architecture the increases will come. I'm with you though, I don't think it'll be more than about 10% clock for clock. But apparently they did manage to do some slight tweaks to get power consumption down. I really want TSMC to get their asses in gear and get the node below 28nm up and running.