Every since the AT&T and T-Mobile merger was announced T-Mobile has been saying business is still the same as it has always been. However, it does seem that T-Mobile’s latest device is being released in preparation for the merger between the two cellular companies.
The spec sheet for the T-Mobile G2X lists AT&T cellular frequencies along with the T-Mobile frequencies. Both T-Mobile and AT&T use the same cell frequencies for their Edge service, while T-mobile uses AWS IV (1700/2100 bands), and AT&T uses UMTS (850/1900 bands) for their higher speeds. Usually, T-Mobiles devices do not include the chips required to handle AT&T’s frequencies. This seems to have changed according to the spec sheet for the G2X which will be compatible on both networks.
AT&T has said that they do plan on switching T-Mobile’s 3G towers to LTE in the future, that way current customers that want to stay after the merger would eventually have to upgrade their phones if they want to take advantage of the higher speeds, unless of course you get the T-Mobile G2x when it is released.
T-Mobile may be trying to make this merger easier on customers by releasing devices that will already be compatible on the AT&T network. However, we could could also be jumping the gun, and maybe LG just wanted to release a world phone since the G2X is also compatible for European frequencies also.