I think a golden Age can only be decreed after the fact. It would be judged on the quality of the ukes made during that period and the music that comes from those ukes. Also, the general public perception of the instrument and its musicians would figure into the equation.
The Golden Age of the Ukulele was from the 20's thru 40's if memory serves me (which it usually does... s**, where are my car keys?). So, do today's premium ukes rival or even surpass the Martins of old? Certainly modern technology would give today's Kalas and Ohanas an advantage over yester-years' factory produced ukes like Harmony and such. What about custom made ukes? I wonder how a Pete Howlett uke would compare against a Nunes. Unfortunately, I'll never know.
As far as the music goes, I'm not a fan of the Vaudville ukers and it seems that the Golden Age of Uke refers to that style of play. Today's ukers usually refer to Jake or James. But who, outside the uke community knows who they are (as opposed to Roy Smeck or Arthur Godfrey in their day)? With players like Aldrine doing so much to spread the knowledge, the New Golden Age can include the vast numbers of ukers we see here on this site and YouTube. Maybe the New Golden Age will be harder to define because the spotlight will shine on so many more than just a mere handful.