And that off hand comment by you makes me think even more that this is quite possibly a pretty much releasable version of the next iPhone.
First the Nexus 1 and now with the Desire and x10, three phones that are not just arguably better than the 3gs but also with big marketing budgets behind them*. Due to these Apple is starting to hemorrhage it's loyal customers, those coming from a 3g (or even 2g) and not seeing the 3Gs as a big enough upgrade and not waiting til a possible June upgrade.
What would you do in a situation like this? "Accidently" lose a prototype somewhere, giving people a peek into what the new one will be like (better than showing it off officially as it may not work properly yet, it's easier to just palm it off as a partially working prototype that was lost than a partially working phone at a conference) and causing all those iPhone (and other) users to stop rushing out and getting the Desire/x10 and wait until the release of the new iPhone.
Personally the phone looks a damn sight better than the old one, although they still have too much space at the top and bottom for my liking. I'll be more interested when we actually find out what it is running under the hood, if it has a higher resolution screen it better have a much faster processor/GFX processor to cope.
*There are other phones before those three that are arguably better, such as the HD, Hero and HD2 but they never got as much marketing as the three now mentioned.