2) iTV, iPhone, webification of all communications
3) Green energy (a wild card)
4) Potential biotech/DNA break through, I don't count on it.
Don't underestimate 1) and 2) because the true wealth from web has not been realized yet. 1995-2000's web 1.0 revolution only paved the road for web 2.0 and iXXX of everything. Web 1.0 only accomplished the goal of cutting cost, but Web 2.0 and iXXX should start to create wealth from Web.
I also bet highly on Green energy. This may be the King card in US's hand to trump other competitions in the world.