For starters:

If your beer were to truly be in outer space, it would suffer from explosive decompression, causing the can to rupture and the beer to vaporize. It would then remain in orbit for several days, then re-enter the Earth's atmosphere and land either in New Zealand or one of Earth's many oceans. This means that the white-hot can moving at high velocities will either stun a Maori tribesman or a cuttlefish.

However, if the beer were to be in a merely zero gravity environment with atmosphere, surface tension would pull the beer to the exterior of the interior of the can, leaving a carbonated void in the center, like so:

/      (Top)   \
|     ____     |
|    /    \    |
|   |      |   |
|   |(Air) |   |
|   |      |   |
|   \______/   |
|              |
|  (Beer)      |
|    ______    |
\___/      \___|

When the can is opened, pressure differentials between the interior of the can and the true station pressure would result in a large spurt of air, mixed with a little beer. While preoccupied with this, previously mentioned surface tension would cause the beer to flow outside of the can, and up your arm. (Note: As a result of zero gravity, surface tension pulls liquids around objects, attempting to envelop them. As a result, the best way to deal with liquids in space is to take a wide paper towel, and position it in the path of the floating liquid. As a result, the fluid will attempt to envelop the towel, and hasten its extermination.)