I like the idea of an environment challenge for sure, but would it have a certain theme or be open ended?
Also, I really loved the fact that this months challenge was modelling only, no worries about having to texture, light and try your best to get an amazing render done.
Would this environment challenge be similar, concentrating on one area of 3D rather than having to worry about 4 or 5 at a time?
Either way I'd have a go at that one if it was chosen.