The 'sig opcount <= 2' rule for tx relaying is slated to change with the 'sendmany' patch I pulled on Monday.
The new rule will be 'sig opcount <= size/34
Code:
// Checking ECDSA signatures is a CPU bottleneck, so to avoid denial-of-service
// attacks disallow transactions with more than one SigOp per 34 bytes.
// 34 bytes because a TxOut is:
// 20-byte address + 8 byte bitcoin amount + 5 bytes of ops + 1 byte script length
if (GetSigOpCount() > nSize / 34 || nSize < 100)
return error("AcceptToMemoryPool() : nonstandard transaction");
// attacks disallow transactions with more than one SigOp per 34 bytes.
// 34 bytes because a TxOut is:
// 20-byte address + 8 byte bitcoin amount + 5 bytes of ops + 1 byte script length
if (GetSigOpCount() > nSize / 34 || nSize < 100)
return error("AcceptToMemoryPool() : nonstandard transaction");