[2008] Looking for GUI Advice / Ideas

We are starting up a rewrite of a large project and I am trying to come up with a redesigned gui. So far, I have played with ribbon controls. I really like the results, but I'm not sure a ribbon is what I need. The software is a full package that uses mdi to bring up modules of software. Different modules exist for Accounting, Employee Management, Orders, etc.

I have attached a blanked out version of a ribbon test. I worry about using a ribbon because- the module bar is the main thing users need, and I don't think it should disappear whenever they click on help, tools, or anything else. Also the ribbon presents a problem with merging menu items of mdi children. Some ribbon controls allow it, but the one we purchased does not. I can get another if necessary, but I wanted to be sure I was using the ribbon before doing so.

I could use a regular toolbar, but I would lose the ability to group related modules together with a description (also not as important, but it allows us to easily place the logo in the top left of the app).

Any thoughts or suggestions would be greatly appreciated.

On a related note, I just read some stuff at a 3rd party control website that said Microsoft believed it was better to move away from mdi. I'm not sure what would be the appropriate way to do that with a project this large.