Might it be that Obama thinks he has to act "bad ass" in order to not appear weak on foreign policy?
Thus Obama may be worse for the Russians than Bush. And I'll give my consent to any government that does not deny a man a living wage-Billy Bragg
Medvedev's omission could be a serious sign. Russia might be comfortable enough with continuation of Bush's power doctrines. How much will Obama dare?
Grabbing what you can, as John Ruskin said, isn't any less wicked when you grab it with the power of your brains than with the power of your fists.
However, it is interesting to think, how much racist shades Russian rulers may have.