I'm a little concerned that some people might think using it makes reissued transactions safe— like apparently MtGOX does!— when it doesn't, you must double-spend for mutual exclusion safety.

But other than that, it sounded potentially useful to me.  Code at: https://github.com/sipa/bitcoin/commits/normtxid

I worry that if we don't use the Bitcoin transaction mechanisms for masking (as that patch does) it'll never get all the malleability right, but if we do people will have a hard time reimplementing in objective brainfuck correctly.

Probably beyond comment on that approach we need another implementation in not-C++ and do a test on the testnet and bitcoin blockchains and see that the implementations agree on all txn, then again with random fuzzing.