Okay, to avoid getting "lost in translation", here's the 10meters.com definition of what CDMA is (weird convoluted jargon, and explanation of why it is important included):

CDMA - Code Division Multiple Access got its start as a military technology, developed by the Allies in WWII. Much like data sent over the Internet, CDMA conversations are "spread" when sent, then reassembled upon arrival. The technology allows multiple calls to be carried over one channel. CDMA is the fastest-growing transmission technology and is basically the multiplexing platform for 3G. It is considered an efficient and secure technology, and it operates at lower power, which conserves batteries. CDMA carriers: Verizon, Sprint PCS. CDMA champion: Qualcomm. Estimated number of users: 67 million.

AT&T uses GSM; all of AT&T's major rivals, Verizon Wireless and Sprint, are both CDMA companies. This means that if you want to use the iPhone, you better be on AT&T and GSM.

A lot have said that the regardless of the "Appleness" of the new iPhone, the experience with the product will ultimately have to depend on the service it's on. So we ask you iPhone eager folks: Are you OK with being on AT&T exclusively? Let us know in the comments.

On a related note, some witty folks are now speculating that you may see a Verizon CDMA zunephone. (But how plausible is that one?)