Interior rendering with Cycles and Faking IES lights
If you try to compare the features offered by Blender Cycles with older and more mature render engines like LuxRender, you will notice that Cycles is in fact a very young render engine, and still has a lot of development ahead. But, with some creativity we can work around some of those missing features to render really impressive images for architecture. For instance, just take a look on the image below posted by marcoG_ita at the Blenderartists user forums. He is using a clever technique posted at the forums to fake IES lights in Cycles.
I strongly recommend you to check out the tutorial about fake IES lights on Cycles, which will be useful to render rooms and interior scopes.
More views at the forum post.