I'd love to hear about an observed star like this, but at the same time I'm very skeptical of this prediction. We've created strange quarks in particle accelerators, but they decay in 10^-10 seconds. So the prior theory (that they may exist for a brief instant as a stage in the star's collapse) seems to correlate more closely to actual observation. The new theory suggests a way for the star to obtain equilibrium, keeping the quarks in that state while burning them.
Hopefully now that they know what to look for, we can turn the prediction into observation.
...a very small fraction of the energy will be emitted as electromagnetic radiation (i.e. light), making these objects very hard to detect.
oh...
Well then, for the time being I'm more inclined to side with the other guy in the article:
"It highly implausible that such an electroweak star would exist," said Paolo Gondolo of the University of Utah.