Yes, very true, but this is in part because silicon is simply understood so well now. Trust me when I say we could do just as exciting things and more besides with other materials if we just understood them half as well!
To illustrate what I mean, consider the fact that the Czochralski process [1] exists and that it means you can get huge, pure, relatively defect-free ingots of silicon (see [2]). With new materials, we're happy just to grow a few microns of the stuff, let alone something like that.
So you're right, silicon really is very incredible :) but we've reached the point now that the new innovations are in part possible by sheer momentum alone, like the billions of dollars of investment you mention. The big challenge is to develop new materials that initially (possibly for decades or more) are inferior to silicon but might ultimately unseat it. The only problem is that no one really knows what that material will be in advance. A lot of people right now are gambling on graphene, and from the amount of investment alone something interesting should come from it, but who knows if there's something else better out there just waiting for the attention it needs.
[1] http://en.wikipedia.org/wiki/Czochralski_process
[2] http://en.wikipedia.org/wiki/File:Monokristalines_Silizium_f...