I have had 3 game crashes in 3 attempts to play today.
I was doing inferno experience runs and twice in a row the game crashed and the application quit in a flash in both cases. In both cases, I had started inferno with MP3, began in the core of arrest, made my way from the town portal at the end to the waypoint, took the waypoint to stonefort, ducked into the skycrown battlements and just as I turned into the stairs, the game disappeared.
The third instance the game crashed was also in the skycrown battlements area but a bit further along in the area.
I am playing on Mac OS X