It may not be "the solution", but no one in Deep Mind said it was. It doesn't particularly matter how journalists spin this stuff, as they clearly don't understand it anyway.
By the way, if Monte Carlo search worked, then we would have seen MC beating 9-dan pro's long ago, which clearly didn't happen, so the author's definition of "effective" lacks pragmatic insight - the real limiting factor in this sort of evaluative judgment.
The author doesn't seem to have watched any of the matches of AlphaGo vs Lee Sedol, though, as much of the pre-game and post-game discussion brings to light some important details surrounding specific implementation features in AlphaGo by Deep Mind. Glossing over that makes this article remarkably uncritical and uninformative.
Edit: it's one thing to combat hype, but representing the facts as they are in contradistinction to that hype is another matter entirely. Anti-hype is perhaps more pernicious in bringing about an "AI Winter" than is drumming up interest in what AI, or more accurately AGI, will be capable of in the not-too-distant future. And given current developments, I think the only AI Winter we have to fear is the one where uninformed persons accost us with misguided fears about AI and what its capabilities will be.