Is the proposed "Miner Promise" method of accepting 0-confirmation transactions safe? This thread proposes a method for miners to promise "that their next block/s will contain a specific transaction", and/or that "they won't mine a conflicting transaction".

If adopted by a large percentage of miners, this method is supposed to enable "relatively safe" 0-confirmation transactions (well, safer than today at least).

If wildly adopted, could this work?
I don't think it helps much. The biggest real threat is the Finney attack, and the Finney attack is just as big a threat even with such a promise.