IIRC, there was a report from the Foundation that an issue was found on a pre-production A board that won't be addressed until production of A boards in volume is needed (expected primarily for the educational market). When both A and B boards are proven to be bulletproof in their volume production, the OS ports are relatively stable, and enough useful and eye-popping application software is available (beyond what already exists on other platforms), it is entirely conceivable that demand could swell into the millions just for the education market.
Tens of millions worldwide is even well within the realm of reality. The low power requirements and price of the Pi makes it attractive to the underdeveloped world, particularly where electrical power comes from sources such as solar, wind, etc., and not just for education.
The best things in life aren't things ... but, a Pi comes pretty darned close!
"Education is not the filling of a pail, but the lighting of a fire." -- W.B. Yeats
In theory, theory & practice are the same - in practice, they aren't!!!