I saw a program on the science channel had a program mentioning that the human race will be changing. Either through genetics or adaption to environment. The human race will be around in 3 billion years but not as the current Homo Sapiens..
Who you callin a Homo . . . Sapien?
Seriously though I disagree and I agree. I think humanity will manage to somehow spread life to a different planet. It clearly won't be human, but since we all emerged from a primordial goo at some point, it will be related to us.
Of course 3 billion years might as well be eternity.
As I said before, an unimpeded contiuation of humanity's exponential acqusition of wealth and knowledge will mean we overwhelm the entire universe in less than 100,000 years.
Something will have to give.