I don't see how you can say that there's no difference between the 3GS and the 5. As you said, there may be no compelling reason for you to upgrade, but to say that they are "the same" is simply untrue.
As a 4S user (having also owned the 3G and the 3GS), I'll admit that I wasn't blown away at all by the announcement, but I'll still pressure my wife into giving me her upgrade so I can get one. It's simply not possible for a company to completely revolutionize a market with every single device, especially on an annual release cycle. We were blown away by the iPhone in 2007 because the market was so different. But the market landscape has changed so much in the past 5 years that the kind of change we expect is just not possible.
As a 4S user (having also owned the 3G and the 3GS), I'll admit that I wasn't blown away at all by the announcement, but I'll still pressure my wife into giving me her upgrade so I can get one. It's simply not possible for a company to completely revolutionize a market with every single device, especially on an annual release cycle. We were blown away by the iPhone in 2007 because the market was so different. But the market landscape has changed so much in the past 5 years that the kind of change we expect is just not possible.