Yeah, last time we were in there there were large sections of rotten ice (water at the surface) which made the ski across a bit more exciting than I would have liked.
A few days ago, we cut holes with our ice axes- the ice varied from 2-4 inches thick within a few hundred yards of shore. From Panorama ridge, it looked much thinner near the Burton Hut and Sphinx Bay, though the whole lake was frozen.