Every one of those growth months [since February 2009] included the launch of a hit game. September 2009 included Halo 3: ODST and The Beatles: Rock Band. Then God of War III, Pokemon SoulSilver/HeartGold, and Final Fantasy XIII launched in March 2010. Both Red Dead Redemption and Super Mario Galaxy 2 pushed May 2010 into a growth month. Fallout: New Vegas, NBA 2K11, and Medal of Honor topped a list of million sellers in October 2010. The rest of the list is predictably full of titles you've heard of, and likely even played.
So, yes, the growth months have had extraordinary release slates, particularly for games that are part of established franchises that have historically sold well. These games are not only popular, but are often promoted more than untested games, creating a feedback loop that helps propel the big games further.
However, sometimes there are big games released and things go the other way. March's sales are just such an example, I believe. The top 10, as shown in the table below, contains several new releases with licenses that ought to help push the industry higher, not lower: Mass Effect, Resident Evil, SSX, Street Fighter, Tekken, and Mario.