WoT devs have this in a closed test to trial the two gun mechanics. As can be seen the model is finished in HD. Some early info. There are two versions of the mechanic in testing one of which will go into the Game. It is also interesting that the current client is able to support this two-gun mechanic.
Types of shooting: you can immediately shoot two guns and wait 10-17 seconds to reload, or shoot the guns alternately ever 5-7 seconds.