It's annoying only in the sense that we all want what we can't have (or can't justify), and shiny new iPhones are one of the most tempting gadgets on earth.
Last year my wife and I upgraded our 3G iPhones to the 3GS. We were only a year into our contracts, but eBay-ing the old phones got us almost the entire new contract subsidy back (we got $300 each), plus we got the "early upgrade" discount from AT&T. So that's always an option for you frequent upgraders. The iPhone holds its value like a Honda.
I feel pretty confident that the 3GS will carry us to the end of our new contracts in 2011. The speed was the big draw. I JUST HATE LAG. None to speak of on the 3GS. I'm very happy.
So I'm not expecting a big enough bump next year to make me drool too much. At least, there's nothing about my 3GS that I'm unhappy with, in comparison to the 3G where I was annoyed with the lag.
Of course, an 800x600 screen would catch my attention, but I'm really not expecting that.