Hate to break it to ya, but seems like you have no idea what you're talking about. The iPhone 5 will be a minor update? Since when has Apple ever released a minor update for the iPhone?
Don't say iPhone 3G to iPhone 3GS, because that was a huge jump in internal specs, that's why it's still being able to run iOS 4 fine.
A Dual Core A5 chip for the iPhone 5 itself makes it a massive upgrade, not to mention the other features it's going to get, so Apple will make iPhone 4 owners upgrade.
I find it unfair that people who are stuck in long contracts with their iPhone 4 are trying to undermine the next iPhone so that they feel better about themselves.
Also, i find it odd that people associate a major upgrade to the device, if the externals are the different, don't judge a book by it's cover guys.
In fact, i'd be surprised if Apple didn't change the design of the iPhone. Sorry guys, but the iPhone 4's design is completely plagued with bad press, and more negativity than any iPhone before it. Biggest being the antennagate issue. No surprise that the guy in charge of the antenna design was fired/left Apple soon after the complaints came running in.
just my 2 cents.