Ask each of your developers who the three best developers in the company are. Only ask the developers — managers can't answer because they're in no good position to know. Average out the votes and produce a consensus 'top three' list. Hold on to it, and repeat the survey every six month.
If over a year has passed and two of those three people are still on the list, your company is probably screwed. You might not actually have realized it yet, but that doesn't make it any less true. Your management or business metrics may actually be positive, but if your development team isn't improving, the technology underlying everything is stagnating and sooner or later the smell will reach your customers.
Unless you already employ the best programers in the world, of course.
And if you really and truly believe that you employ the best programmers in the world, then unless your company name rhymes with 'Foogle', 'Schnapple', or 'Sicromoft', you're probably really screwed.