I would consider such questions explicitly off topic for this site. This site is for users of Mathematica (mma), not Wolfram|Alpha (W|A) and so any question that does not involve the former is out of this site's scope. I know that W|A runs on mma and it kinda sorta understands mma syntax. However, opening the door to such questions will only lower the bar and result in hit-and-run questions from folks who just want a quick result from W|A.
Along the same lines, questions that merely concern the Free-form input (=) or the Wolfram|Alpha query (==), which is available from within mma from v8 onwards, without any further processing in mma should also be explicitly off-topic, as this is just a back-door for W|A questions by masking it in an mma call.
On the other hand, questions that involve interfacing with W|A from mma, and using the results from certain pods for further analysis/manipulation in mma should be considered on-topic. Vitaliy Kaurov's answer here on Stack Overflow is a good example of such questions (although I note that the question itself did not ask for a W|A based solution).
