I agree, it isn't magic, but it's extremely useful, if not essential--IMO.
The story behind ZMA isn't as transparent as some would think. It, by far, is one of the top supplements I recommend to all athletes and non-athletes alike that I do nutritional counseling for.
It was initially pitched as a "testosterone" supplement based on a very poorly conducted study on football players. Numerous studies thereafter failed to find any massive benefit---at least a quantifiable one.
The reason it IS useful it multiple-fold: Our diets are (generally speaking) devoid of any decent amounts of either magnesium or zinc. As athletes, we end up utilizing AND excreting what we have to a much larger degree than sedentary folks. Poliquin states that nearly every single athlete that he sees is deficient, and the zinc tally test is a done as a standard baseline.
Another reason for supplementation is that recovery cannot be overrated---training gains are based on consecutive training days, and if you are trashed from the previous day because your recovery sucks, well, so does your training, and so do your gains. Sleep is the key for optimal recovery, and there is no better supplement than ZMA for sleep. It's not just the deep tendon muscle relaxing effects of Mg; zinc enhances REM sleep, and B6 is essential in the conversion of 5-HTP to serotonin (5-HT).
To answer the OP's question: Nope, haven't seen anything new on ZMA, and we probably won't. Recovery is damn hard to quantify, but talk to any athlete that trains at high intensity on a regular basis that uses ZMA, and they'll more than likely put it as their top supplement.