Saying that silicon life is less likely than carbon based life and that general AI is inevitable in the same breath would be a contradiction. I know you didn't mention AI yourself but there are plenty here on HN that would espouse those views.
But if we produce general AI in the near future it will have taken us billions of years, a considerable fraction of all time in this universe.
That would be assuming that the evolutionary progression to organic life as intelligent as humans must follow a similar path. Is there evidence that evolution is directed and that intelligence is some sort of "higher form", or is intelligence an arbitrary adaptation like any other, and could have occurred earlier in history? I could be wrong but I believe the latter is the current interpretation of evolution, in that humans could eventually evolve to something with _less_ intelligence.