I never used Pandora or GMail, but it took me a few seconds to get used to the new Kindle app.
Actually, some of the "learning curve" (for me, anyways) has been fun. It's been like when I first got an iPhone. I mean, most everything works like it always has. But every once in a while, there's some funky change. It's kind of fun figuring it out.
That, or I'm just dumb. :)