More on this site, somewhere. Assuming this result is meaningful*, it's not clear if this is good news or bad news for chess fans. Superficially, it's great news, because it costs money to buy Rybka while anyone can freely download Houdini. BUT: There seems to be a lot of cannibalizing going on among engines** (certainly such accusations are widespread), and if it's true that the free programs are ripping off code and concepts from the for-profit engines, it's likely that sooner or later the for-profit people will simply leave. Then the cannibals will have to do their own work, and with no financial incentive or notoriety to inspire them, the field will stagnate. Then it's not only a pity for the legitimate programmers whose work and financial opportunities were stolen, but for the broad chess community as well.
* There are reasons why it may not be so significant: the computers may have used truncated or common books, and a 40 game match, while not trivial, doesn't guarantee that Houdini is the stronger engine. Still, the evidence that's there, of whatever quality, is in Houdini's favor.
** As far as I know, no one has accused Houdini of pirating code from a closed-source engines, but its author has acknowledged being influenced by engines that have allegedly done so.