Re: Alert: chain fork caused by pre-0.8 clients dealing badly with large blocks
A hard fork like this would require the intentional support of a majority of merchants.
Sure. But how is it unintentional to accept blocks longer than 250KB, after the "majority" (expressed in the hashing power) upgraded their clients to a version that accepts blocks larger than 250KB? 
And they upgraded it not because they had no reason - they actually had a very good reason.