There is a Technology Preview of TG2 available for download. If you have used Terragen, you will see some familar features, but the new node system for objects and shaders will draw your attention or repel. There is also an instancing feature so you can populate a landscape with trees, grass, stones, etc.

Including the preview download, there is also a sampler of 15 Xfrog trees available to download. These are in terragen object (tgo) format.