My point was that twitter's scale and problem complexity are not unprecedented and that small, motivated teams have solved them before. Parallel queries and transactions for DB2 on z/OS were developed by small teams in Poughkeepsie, NY and Perth, Australia. Google's infrastructural software was designed by a small group of very bright people, and so on.

If we compare the groups actually working on the problems then I expect that twitter will have comparably small groups of engineers directly facing the scaling problem. And I also repeat the point that bigger problems have already been solved. Twitter's issues are not unprecedented if you are prepared to look outside the Journal of Stuff I Remember Seeing on Highscalability.com.