True, I had a friend debating whether to get one. I asked him, if they had labeled it a 5 would you feel the same way, what missing features are you after exactly? Turns out it pretty much was just the branding.
Perhaps part of it is this: I have an iPhone 3GS and didn't upgrade to an iPhone 4 when it came out because I was locked into my contract. By the time my contract ended, the 4 was 8 months old and I decided to hold off on upgrading until the 5 came out.
By releasing a 4s, Apple is most likely signaling that there will be a radically new phone released soon. (less than a year) I'm going to get a 4s (the new features are great and I can't really wait 6 months) but I probably won't ever actually get the 5 due to carrier lock-in.
A lot of people don't know this but the resale value of last years iphone is usually ~ the subsidized cost of this year's phone + cancellation cost for last part of your contract. There's a bit of a skew to this this year since the 4S came out later then usual.
Example:
(1) cancellation fee after 12 months at ATT is $325 - 120 = $205. If you had bought an iphone 4 in July 2010 the cancellation fee today would be $165.
(2) new iphone costs $200
(3) a 16 month old iphone 4 in good condition sells on ebay today for between $350-$375. A few months ago that was around $400+.
This is a twist on the old Jade plan for Macbook upgrades where you sell your old Macbook every year and buy a new one, always staying under warranty and continually upgrading -- it's not flawless, you will have to shell out a few bucks here and there but it's a pretty good system.