I like real-time visualisation tools, so when a new one comes along it is always fun. I am looking forward to playing with Lumion soon, but I will let Steve dive in there first while I look at other things.
As the promo vid shows, the Lumion toolset delivers a pretty elegant real-time experience and with the nice pricing model and hopefully a nice interface for people it could be a cool way to show off design work. If the pipeline from your Architectural modeller of choice (formats: DAE, FBX, MAX, 3DS, OBJ) can get things in and going quickly then it could work for clients as well as design studio tutors. This next video shows a tutorial from importing from Sketchup to materials etc - very smooth and quick if you like using the built-in textures:
The water is pretty nice, and the speed of the process looks viable for any user. Like many of the toolsets of this type, I can see their viability for people hinging on the library and the easy of supplementing the library.
[Promo shots for Lumion via the official site - shrunk]
Oneof the tricks is still that the workflow is still very much a one-way thing. This maker iterating designs complex still as all the work done on a model in the Lumion interface would need to be repeated after making a change in sketchup then coming back in again.
Path forward might be to allow a 'mapping' of sketchup materials to Lumion versions which you do once, then each time you import all the changes come leaping in all materialised already...