Can the DHT22's unique 1-wire-ish interface be daisy chained (like the Dallas 1-wire stuff)?
Will the DHT22's accuracy remain constant or drift and will it be consistent across a variety of DHT22s?
Is there another temp/humidity sensor available that would work better without breaking the budget, perhaps a Dallas 1-wire sensor?
What does it take to weatherproof these for outdoor use?
Are there other questions I should be asking of these sensors?