Good point. Knowing my players, they'll be unbeatable at skill challenges involving bluff and insight, but crap at everything else. Well, until they catch on.
Actually, I don't know about other people's party's but my players will have one or two Skilly McAwsomes in bluff, insight, and diplomacy, with another in thievery (actually, that may be the same guy depending on the campaign), and a third in arcana.
I wonder how that works out overall. With skill challenges where we have a Skilly McAwsome, they win. But when he's taken away, they usually lose. Of course they don't lose as often in that scenario as often as the win in the other, so what would the overall win ratio be? How often is Skilly McAwsome a factor? I could be missing something, but it seems the more common he is, the more often the whole party wins, all other factors reflecting Stalker0's tables.