I RTFA and it seems the author is confused. The announcement 3 years ago was that Jeff invested in them, that's all. And like Amazon, 37Signals is pretty traditional and I see no indication of some "big idea" on the horizon, other than the big idea of running a profitable/growing/thriving business.

There's also no meat to the article, just a "hey what's up with that?" comment in regards to over-valued web companies and 37signals strong conviction to staying ... real.