everyone should familiarize themselves with any website that includes phone specs.
Phonearena.com is an excellent source of information.
When looking at a phone's spec sheet, it will be clear whenever a phone is a "world phone" versus one that is not. If it only has CDMA radios, it is not a world phone, though it can roam on any CDMA network. If it is a GSM phone, same concept. If the phone has both CDMA and GSM radios, it is a world phone.
I take it quite a few people are also not going to understand the fact that the whole word doesn't use a single type of cell network. For most people this is never an issue, but some will decry the lack of compatibility. I find it amusing people will assume things like this and blame their network provider or phone manufacturer for not informing them, but this is hardly an issue that is only applicable to cell phones. Consumers simply need to understand that buying without research is simply nobody's fault but their own.
However, I completely understand the frustration of being assured that this phone is a world phone. However, do understand that you do have a "half-world" phone. Quite a few countries have a dominant CDMA presence, if not CDMA only. Japan has CDMA service everywhere IIRC, as do I believe a few other Asian countries have their entire service areas covered in CDMA (again, possibly with GSM coverage too), while Europe is entirely GSM only.
I believe Motorola stated to achieve the dimensions of the phone, they could not include both types of radios. Additionally, that "chin" at the bottom is there for the sole reason of housing the radios as it is.
It would be nice if in the near future, Motorola develops a world-phone variant of the Droid, and it is likely a world phone phone will be developed with Motorola shifting their focus to Android entirely (though they supposedly have a keen interest in Windows Mobile 7, they stated they are ditching the WinMo platform for now, possibly to return with WinMo7). Whether or not it resembles the Droid or is simply a different exterior design with the Android OS is a different matter, though as a side note, it's absolutely not guaranteed Motorola will ever develop an Android world-phone.
As Android continues to gain more attention, more Android world phones will certainly be released.