Well -- that didn't take long. It was only yesterday we let you all know that the Samsung Mesmerize would be getting Gingerbread rolled out to it shortly. At the time, we didn't know when exactly but apparently US Cellular did and in fact -- it's rolling out now. If you're looking for the full details you can check out the source link below, otherwise head on into the Samsung Mesmerize forums and let us know how the update went for you.
Source: US Cellular; Thanks, Reid!