Activision has said that Miis, like Xbox Live Avatars, will be supported in Guitar Hero 5.
Support for PS3 Home Avatars, on the other hand, is unlikely.
"While there are no plans to have Home Avatars for the PS3 version, the US has confirmed that Wii owners will be able to rock out with their Miis in Mii Freestyle Mode," a spokesperson for the publisher told us.
The publisher went on to explain that Xbox Live Avatars will not retain in-game clothes and accessories when outside of Guitar Hero 5.
Guitar Hero 5 will be released on 18th September for PS2, PS3, Wii and Xbox 360. Head over to Eurogamer TV for a clip of the Xbox Live Avatars in action.