Hi,
Although I see the usage of such a tool for personal usage, I don't consider this kind of tool useful for developers. The EULA of the image providers doesn't allow developers to distribute the scenery made using Google Earth or similar providers. So developer will get their imagery from other sources that allow distribution and process them typically with resample.
I have a scenProc feature in development that can take WMS sources, download them and process them into photo scenery using resample. But scenProc is not the kind of easy to use tool you are talking about here.
The new 3D city models with the realistic buildings that Google has for certain cities looks great indeed, but I'm not sure what kind of data is behind it. It seems to be a very accurate elevation model with imagery that is placed over it. That kind of technique is not really compatible with how FS works. And on the other hand I also never found any reference to how you can buy/get the underlaying data. It doesn't seem that Google even sells these models.