[scott_w]

Not really. Returning hetergeneous data is perfectly RESTful if that is what the endpoint describes. You might want to be more descriptive in the URL, however:

/dashboard?type=orders&type=customers&type=support

With either some documentation explaining the differences, or even the return value itself describing what's in e.g.

{"orders": {"date": "today", "data": [...]}, ... }

What you return depends entirely on the context of your web service. If people are telling you to always return a homogenous set of results then they're wrong. You know your application better than some random guy on the internet.