http://toucharcade.com/2008/07/07/under-the-hood-the-iphones-gaming-mettle/If you are correct then you just answered the question I was just about to post regarding if the iphone 3g and 2nd gen touch shared the same processor with one just being overclocked by nearly a 1/3 percent increase in power or if the touch indeed does have an advanced, revised chip inside.
According to this article the 2nd Gen Touch uses a revision 4.0 while the others uses a revision 1.0. I don't remember any of the tear-downs mentioning the chip being smaller so a process shrink is unlikely. It's just due to a maturing product.The Samsung chipset at the heart of the iPhone utilizes a 32-bit RISC ARM processing core, the ARM1176JZ(F)-S v1.0. The ARM device is capable of running at 620MHz, but Apple has downclocked it to 412MHz, presumably in the interest of extending battery life. (Apple has, at least once in the past, adjusted the clockspeed of both the processor and the system bus via firmware update.) Unlike the original iPhone, the 3G iPhone and the original iPod touch, the second-generation iPod touch features an ARM1176 v4.0 core running at 532MHz.