2 BTC and up -always- requires confirmation [this is after hundreds of games], regardless of the fee attached.  I know my 1 BTC bets used to get instant response when they had a fee attached, but I never made any between 1 and 2 to determine where the exact cutoff was.

It would be nice to have the old instantaneous SatoshiDice back, but I can certainly understand the need to wait for confirmations on large bets.  It's just too easy to attempt a double spend when you lose, and on large bets, there is significant incentive to do so.