The Danish Ministry of Transport has succesfully migrated to LibreOffice. The project is called 180 degrees and consist of several parts. One is migrating away from MS Office to LibreOffice. The translated story (please note that the amount is DKK and not USD):

http://translate.google.com/translate?sl=da&tl=en&js=n&prev=_t&hl=da&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwww.version2.dk%2Fartikel%2Fministerium-faar-milliongevinst-med-skift-til-virtuelle-desktoppe-og-libreoffice-44101

The business case (please note that the amount is DKK and not USD):
http://translate.google.com/translate?sl=da&tl=en&js=n&prev=_t&hl=da&ie=UTF-8&layout=2&eotf=1&u=http%3A%2F%2Fwww.magenta-aps.dk%2Fopenoffice%2Ftrm_case%2F