Google Earth does use QT.

Take a look in:

C:\Program Files\Google\Google Earth Plus

for qt*.dll

does this mean it'll be another six months before the mac version comes out?

Since I see not specific Macintosh requirements in the description, I'd guess it has no bearing on how quickly a Mac clients is completed.

The whole point of choosing the QT development environment and API is that they can, as they say in their "Other Platforms" hint on the download page, hope to release for Linux and Mac as soon as possible.

QT can't support the graphics rendering so I would hazard a guess they'll standardise on an OpenGL library optimized for each platform and GE.

Of course, if it'd have been me I'd have gone with Java... maybe they need to go have a word now they're in bed together :)

Right, but that doesn't mean a Mac client is expected. For all we know it is Solaris. *cough*