Puck Prospectus has come up with a definition of a quality start for a goalie, and has a list of the leaders and trailers in the category for this season. Their definition of a quality start is a game with a save percentage above .912, or a save percentage between .883 and .912 while allowing 2 goals or less.
Defining and measuring quality starts is something I have hacked around a bit with, and I know others have as well. I think most quality start definitions include something to do with 2 goals or less, just because the winning percentage splits drop so dramatically for a team once that third goal goes in. The problem is that there is obviously a team element involved, stopping 14/16 is usually quite different than stopping 39/41, but save percentage is also team-influenced.
My ideal quality start would be awarded whenever a goalie allows fewer goals against than expected based on the shots he faced, but that would require a detailed shot quality analysis for every single game to determine.
Perhaps the most interesting bit in the article was pointing out that the median save percentage was .912. Last I checked the average was around .907, which shows how bad games can have a disproportionate impact on goalie stats. There isn't much difference between letting up 5 goals or 9 goals, in both cases your team is going to lose nearly all of the time, but obviously the latter figure is going to have a bigger impact on a goalie's save stats. Henrik Lundqvist is one example of a goalie who seems to have a couple of games a year where he gets shelled for 7 goals on 20 shots or something like that but is otherwise pretty consistent.
It is probably a good idea to look at metrics like quality starts to avoid penalizing goalies too much for a few bad games that really hurt their seasonal GAA and save percentage stats, or on the other hand to see if goalies that record a lot of shutouts are really putting up excellent performances from game-to-game.