my boss showed me his 3G S, (financial analysts for investment banks get access to new products before the public so we can asses for ourselves how much value it will add to the company as a whole and their revenue stream)
anyways.. it's not as fast as you think, and truthfully, I can't remember anyone prior to the 3G S release complain that the 3G was "too slow"
anyways..we came up with the conclusion that the only reason apple released the 3G S was because they had to drop the price of the 3G so the Pre would not steal market share... and also, last time they dropped the price by a $100 their sales increased by 100%...
so apple wanted to increase sales, but they also wanted to have an expensive phone like the 3G S in the line up so they would not decrease sales of their "expensive" phone..
that is also why the stock actually dropped on the day of the release, because we knew a new phone was coming on June 8th, (I actually posted a thread about it a week before the 8th which I discussed the price drop and the new iphone..) but analysts expected a "new" iphone, not just the same 3G with a couple easy to install apps..and a better camera..
it's just a marketing scheme, and that is what apple is known for...
so if you currently own a 3G, you're better off waiting for one year till you buy the real new iphone.. instead of paying extra for the same phone just with a few minor differences and extra space..