The chart you linked shows an initial fast growth, then a Xmas 2006 flection then a rise during 2007 and a rise for Xmas 2007, followed by a growth during more than the first half of 2008, followed by a flection during Autumn and Xmas 2008, there are highs and lows, not a constant fall, while it's still too early to say anything about 2009, we're in the middle of the normal after Xmas dead period.
But as not even Sony at its best can beat Nintendo on handhelds, even just surviving and earning is not so bad. Sony ruined the movies part, it's undeniable, the reason I mentioned are only a short list of its errors.
About Zune, the comparison was for analogy, a big player entering a market thinking it can beat its leaders easily, it's not so easy, and MS got losses from it while Sony had profits despite an embarassing sequence of clumsy mistakes.







