I love the idea, but conceptual and economically, I find the idea of using one sensor in a multisensor device on a long term basis problematic. I'd prefer a modular system where I can provide a wifi base module with specific sensors as required through plugin parts.
It feels wrong, I agree, but the individual sensors are dirt cheap. From poking around on farnell.com, it seems likely that the total bulk value of the sensors is probably south of a few dollars per unit, which is much, much cheaper than introducing the complexity and brittleness of modularity.
Lovely project in any case.