You can accomplish that by checking the return value. But Solidity doesn't have try/catch, it just rolls back everything upon throw. If send() were to actually throw upon failure, then it would roll back the entire method call and nobody gets paid. A troublemaker could use an account that always throws when it receives funds, and permanently block all payouts for everybody (unless a contract admin has a way to kill accounts).

The best pattern is not to put sends in a loop at all. Just update a ledger inside the contract, and have each user call a withdraw() function to get their money. That way if you're careful you can even use call.value, so users can include as much gas as required, and can withdraw the money directly into any sort of contract they like.