Curious: Sanyo presents the…GH2!

As you know Panasonic owns Sanyo since 2009. So it is a little bit strange that Sanyo unveiled their latest GH2 full-HD cam. Why has Sanyo/Panasonic choosen that name? Does it mean that the next Panasonic GH1 successor will have a different name?
There must be some reason behind that choice…