This is a really neat technology that Noda (the author of the article) has been plugging away at for decades. The main problem, from my understanding, is that people haven't been able to find applications.
We already have conventional laser diodes that work extremely well, they're not that bright but bright enough to make laser pointers, disc read/write heads, etc., which are applications where miniaturization is important.
On the other hand, in industrial applications like cutting steel, we have fiber lasers. Those are about the size of a briefcase, compared to the photonic crystal lasers in this article which about a centimeter. But they can reach incredible brightness, about 1000x the output power of the photonic crystal lasers (and about 1,000,000 times that of ordinary laser diodes). And in industrial applications you don't really need the laser to be miniaturized (especially since the power source itself will be a chonky piece of equipment).
So somehow, right now this neat tech is falling into the cracks. One day, I'm sure someone will find the perfect application for it, though.
Edit: the potential application that people are most hopeful about is lidar; if, in the future, lidar gets integrated into consumer electronic devices like cellphones, then photonic crystal lasers will probably prove their usefulness.
I think those use normal VCSELs. To justify using PCSELs, maybe it would be lidars for long range sensing, like range finding over dozens of meters or something.
Now hold on...I can see that being useful too. Two consecutive failed face IDs? BAM!!!* face melting laser on the (probably) unauthorized person trying to access your phone.
