I just ordered (and took delivery of...) a 2005 bike (unused). It's the exact one I wanted because it was the only year they made it in titanium. The only 'drawback' that I could think of was that 1) It's already 'old' should I decide to sell it and 2) it's a 9-speed where the newer models are 10. Personally, I'm thrilled with it and I couldn't care less about 1 less cassette ring!

I do know people that need to have the newest stuff...so buying an previous year's model would eat at them. MOST people are not this way though, so if you aren't (and everything else is what you want), then I'd go for it!