Alito may have voted this way, just to make a point to the left that he isn't a "racist." Or it could be that he didn't feel he could get up to speed on the case that quick, so his vote was on the side of caution. Let't wait and see how he votes on the actual case. This was just an vote to hear the case.
BINGO! That was my first thought as well. He just got there- hardly had time to have his robes fitted.
I'm disappointed when I see FReepers jump to conclusions- kinda like knee-jerk liberals.
Although I believe your second explanation is the most likely, I've had fun this morning speculating that Alito is merely trying to establish his credentials as unabashedly Pro-Life.