The IGN (Institut Géographique National) of France should launch soon (june) a GeoPortail looking like a real clone of GoogleEarth. The june version will be in 2D only and in the beginning of the 3D should be online.
I really doubt the 3D version will offer enough speed to be seen online. But we will have a good cue in june with the first version. They have plan to also release an API but the different services involved have not make an agreement yet.