Thank you ndeewolfwood, that's very helpful.
Interestingly Side Effects website lists 543 downloads for TG Terrain, so a lot of Houdini users are using Terragen!
Downloaded the Digital Asset from Side Effects website and the video from Vimeo, it's much sharper playing back in Adobe Media Player (on Mac OS X) than trying to play it on Vimeo.
Given the lack of support for exporting camera animation from CINEMA 4D at this time one option would be to export the camera animation from CINEMA 4D via Houdini (or Maya if you don't have Houdini, but have Maya) to TG2.
Did a test of creating a very simple camera animation in CINEMA 4D exporting to FBX and importing into Houdini. That works with two minor issues, firstly you need to have the Project Scale in CINEMA 4D set to meters, secondly the camera needs to be adjusted in Houdini by -90 degrees on the y-axis.
Next step is to investigate the TG Terrain Digital Asset and video.
Did some more research on exporting directly from CINEMA 4D, there was a thread on this
http://forums.planetside.co.uk/index.php?topic=8679.0. However the SteadyCHAN C4D Cam To TG2 Animation Plugin is no longer available.
In general I would say that it is much better if the developer of the software handles the integration with other apps. My experience is that plugin developers often loose interest after a year or two, or become busy with other work, and plugins then all to frequently cease to work in new versions!
Does anyone have any other suggestions regarding exporting camera animation from CINEMA directly?