Well, it took some time, but Logitech has finally released a new version of the G5 that features the much-requested second thumb button. This is basically a return to the same design that had been featured on the earlier MX518 and MX510 mice, and one that shouldn't have been changed in the first place. Officially, Logitech is calling this new mouse the same as its predecessor - the 'G5 Laser Mouse'. I'm referring to it as the G5 Revision 2, since it's clearly an upgraded version of the original.