Both the United Kingdom and New Zealand are adopting the 7.62mm version of the FN MINIMI machine gun.
The NZ Defense Force is procuring (PDF link) the 7.62mm model, along with ACOG scopes, micro red dots and ground mounts to replace their 5.56mm model. The UK Ministry of Defense is procuring a limited number and so are not replacing their 5.56mm MINIMI LMGs or 7.62mm FN MAG GPMGs.
Other countries using the 7.62mm MINIMI are the Spanish Navy, Polish Special Forces, the Australian Defense Force (F89 Maximi) and USSOCOM (Mk. 48). I suspect more and more countries are going to start realizing the benefits of the 7.62mm over the 5.56mm. I wonder if the USMC made the right choice going with the 5.56mm M27 IAR. A 7.62mm IAR might have been a better choice.