If I had to guess - the WW marketable band for GSM / HSPA+ is much greater than CDMA overall. While the two largest carriers in the US (Verizon and Sprint) are CDMA their technology is one of the staunchy holdouts. LTE presents some interesting value but the world has switched to GSM in general.
There is pain to being an AT&T and Tmobile customer no doubt but that pain does equate to freedom in device choices... Buying phones from Europe is a breeze (of course you have the capital costs but when you are a Geek that budget is traditionally larger
) I suspect that HTC will lead the way with Samsung a close second (Korea is the largest CDMA network outside of the US.) I wouldn't expect to see any LG phones or Dell phones on CDMA/LTE right away (throw the Asus variant in the list as well.)
Simply put - if you want to stay up on the coolest devices CDMA/LTE is NOT the way to go.