A good move, but not the best move.
The All Star Game For-Players-Who-Are-Not-Injured-And-Have-No-Interest-In-Playing-Hard-Enough-To-Risk-An-Injury is a mostly pointless game that shouldn't determine who is the World Champion.
Using the best record to determine home field advantage is a start. I would like to have the best head-to-head matchup be the first determining factor, IF the two teams played each other in interleague play during the regular season...then best record.