well, halfway at least.
If you cut it in equal parts with a non-frozen beer, you effectively have a beer slushie, which really isn't all that bad. I did the supercooled insta-freeze beer experiment with some Coronas last year, and the resulting beer slushie was surprisingly good (although, let's face it, it's not like Corona is ever really good).
They're Boulevards actually
All the way, and they would have either cracked the bottle, popped the cap, or exploded.