There should be a rule, solely for the post-season, that games are never treated either as rained out before they have become official, or as terminated short of 9 innings, on account of weather. Rather, they would in all cases be suspended and resumed where they left off at the next opportunity.
In the regular season, starting games over or ending them early seems acceptable, but in the post-season the stakes are too high and thus it would leave too bad a taste. We saw this in Game 5, where even the Phillies said they didn't want to win a shortened game (but imagine how irked they would have been had it been washed out after 4 innings with them ahead). Selig lucked into being able to suspend Game 5 because the Rays tied the score. But with the rule change I suggest the umpires would have been able to do this in any event, and the contortions of dragging out an important game under unplayable conditions would not be necessary.