Yesterday RIM posted OS 4.0 upgrade for AT&T Blackberry users. We looked at the site and there is an option to download the OS 4.0 for the 7100g. Maybe it’s a cruel joke by a funny RIM employee but maybe it is more than that. AT&T did buy out Cingular which the 7100g has been slated to be released sometime this month. So it is very possible that the 7100g may come branded by AT&T Wireless.