A family of Microsoft word processing software products for creating web, email, and print documents.
I suspect you mean the 2003 (and earlier) "menu" vs the 2007/2010 "ribbon" user interfaces. Because the 2007 and 2010 ribbons are virtually identical.
So, if your question is more like "can we revert to the menu system in Office 2007/2010" the answer is ... kinda.
You can get freeware and cheap (under $100) "addons" that will add a "Menu Tab" that mostly recreates the menu interface within the ribbon.
Menu Tab addins
http://www.addintools.com/english/menuword/default.htm - menu addin 2007 only, free trial
http://www.ubit.ch/software/ubitmenu-languages/ (free fro private use or 0.65 Eur per user & per language!!!)
http://news.office-watch.com/t/n.aspx?articleid=799&zoneid=12 – a review of UBitMenu
http://software.techrepublic.com.com/abstract.aspx?docid=862867&promo=100511 – Classic Menu for Office 2007 ($30)
http://www.addictivetips.com/microsoft-office/add-classic-menu-in-office-2010/
http://download.cnet.com/Classic-Menu-for-Office-2007/3000-18483_4-10637184.html
http://www.obutilities.com/classicmenu/ - a COM add-in that displays the classic menus and toolbars in Microsoft® Excel® ,Microsoft® Word and Microsoft® PowerPoint® (Office 2007 and 2010).
http://www.indelibleink.com/WordMenu.html - Indelible Ink Word Menu addin
http://software.techrepublic.com.com/abstract.aspx?docid=847883&promo=100511 – Ribbon Customizer for Office 2007 ($40)
http://word.mvps.org/FAQs/Customization/CustomizeRibbon.htm Customizing the Office 2007 user interface. Info about 2 purchased addins, Ribbon Customizer™ and ToolbarToggle™ add-ins for Office 2007. They also have limited functionality trial versions
http://accmsoft.com/office-2007/classic-style-menus-toolbars/ - A powerful and easy-to-use add-in for showing the classic menus and toolbars of Microsoft Office 2003 on Ribbon of Microsoft Office 2007 and 2010.
http://www.indelibleink.com/WordMenu.html - Free version of 2003 menu addin. There are several different install options, quite cool. Installed cleanly on my admin ID, but not in my user ID. Installs a template in the C:\users\USERID\AppData\Roaming\Microsoft\Word\STARTUP folder. WordMenus.dot is the 2003 menu alone. WordMenu.dot is the 2003 menu with the standard toolbar. WordMenusTB is the vertical orientated 2003 menu. It looks like this
http://software.techrepublic.com.com/abstract.aspx?docid=927295 - Saavvii for Microsoft Word 2000, free to try
http://www.toolbartoggle.com/Contact.aspx - ToolbarToggle ($20) - 2 modes, full toggle replacement for Ribbon or Adds new tab to ribbon. Allows customization of menu portion, adding macros using right click “customize togglebar” feature, not Word customize. I haven’t tried it, but if it lives up to propaganda it looks best yet**. 5 day free trial.**