I think the carpet, sand and snow needs some work. I belive they also don't need specular maps on them since (as far as I know) they don't really react to light that much or at all. But since I don't know how to do any of this, im not really the one to say much...
The Bathroom wall really looks good as they are the most exposed to water, so they reflect light more than anything else.
The Plaster wall also looks real. In my room, they do look like that because of the paint. However this is only when the light is close to the wall or is very bright. So you could tone down the spec on that one...
Besides that, everything looks great !
Sorry if I nit-picked your stuff too much...
Computer Specs: Intel Core 2 Duo E7400 2.80GHz @ 1066Mhz FSB 3MB Cache, Dual Channel 8192MB DDR2 PC6400 800MHz RAM, XFX Nvidia Geforce 9800 GTX+ 512MB, XFX 780i SLI Motherboard