Soon Windows 7 will use ribbon as default interface in any Windows programs, like Paint or WordPad, leaving to back default toolbars and menus.
Will you migrate your UI to using ribbons for Windows 7?
The main thing with the new ribbon in Office is NOT the different look and feel. It's the effort and research that went into determining what elements needed to be placed where, how big, and understanding why.
If you're not prepared to duplicate that effort for your own app, it will probably be a bust.