Well it does appear that Samsung keep back all their best wares for the Asian market, Asia seems to get the better mobile phones from Samsung even more than Europe and the United States.
And the proof of the matter is the Samsung SCH-F639 CDMA slider design mobile phone, which looks uncannily like the Samsung U600 ultra slim mobile phone.

Ok yes, that is because the Samsung SCH-F639 is actually the CDMA version of the Samsung U600, and it supports CDMA2000 1X 800 MHz mobile.

Apart from that fact, the Samsung SCH-F639 CDMA slider supports Digital Media Broadcasting, otherwise known as DMB, and DMB allows the Samsung SCH-F639 to receive multimedia signals such as TV, radio, and data casting to the mobile phone.

Besides that, not a great deal of detail on the Samsung SCH-F639, no pricing or availability as yet, but then the Samsung SCH-F639 is for the Asian market so we probably won’t be seeing it over here.

Source — Samsung mobile via Mobilewhack