Akrasia said:
Are these two statements compatible?
Possibly, given the vagueness of the claim that 'D&D is doing fine' ('fine' relative to what?), and/or the possibility that D&D's relative health is independent of WotC's overall health.
Yes, it is possible that the two are compatible. Remember what I said earlier about spin-doctoring. What we do not know is what all Mearls includes under "D&D", nor do we know what he considers as "trucking along fine". His statement may include such things as licensing deals (for computer games, or movies, or other things,etc.), his definition of "D&D" may or may not include minis, or even the whole of WotC for that matter, but we have no way of knowing.
One of the nifty things about larger corporations that I learned while working for Hewlett-Packard (was a contract employee at the time) was that they do not like their employees saying bad things about them and/or their business. Something to keep in mind.
Now, if there were ever an opinion that I would trust above all others, Chris Pramas' would be it. He has worked for WotC, so he understands their corporate culture, he has created his own successful business (one built on solid quality), and his company has survived some nasty disasters (such as the Osseum fiasco). Not only is a designer, but a pretty smart business man as well.
Then again, Mearls is not a businessman, and with WotC being a large corporation (or at least part of one), I am pretty sure that he would quite likely not have access to any of their sales numbers, so anything he says in that regards could possibly be considered office gossip.
In the end, it is up to each individual as to how much weight they give the words of another.