UPDATE: At the History News Network, Kevin Coleman gives us some insight into who exactly is behind the coup:
The significance of this coup is that it is in fact a break from the pattern of past coups. In past Honduran coups, either one political party overthrew the other, preserving their traditional patron-client relations and taking the spoils of the state for those within their patronage network, or the military overthrew a civilian government so that it could stay in power itself, as happened multiple times during the 1960s and 70s. This, however, is the first coup by a united upper class. The Honduran business community united across party lines, deciding that it was worth severing the traditional patron-client relations that they enjoyed through their affiliation with one of the dominant parties so that they could stop Zelaya in his effort to increase the participation of common citizens in the affairs of their government while he also drew the country closer to Venezuela.
A class-based coup cannot be openly declared as such and must instead be articulated through existing political ideologies that allow the group seizing power to represent what they are actually doing as something other than what it is. So as the business, industrial, and news media of the country summoned the repressive power of the military to create the political conditions to rule by the traditional economic and political ideologies that have left the majority of Hondurans in dire poverty, they justified subverting the legal and democratic system as a defense of democracy.
Zelaya may have been corrupt, or at leats self-aggrandizing, but like many Leftist leaders in Latin America he was opposed to the system of power as it exists in his country and that, not this nonsense about defending democracy, is the real reason why he was deposed. A clue to this fact exists in the way our very own right-wingers have covered (or not covered) the situation in Honduras. Not only are their feathers ruffled by Zelaya's anti-Americanism and increasingly close ties to Hugo Sanchez, but being true conservatives, they are also opposed to the redistribution of power from the powerful to the less powerful. Not being an expert on Honduras my insight is worth less than even two cents, but it seems to me that those behind the coup (rightly or wrongly) feared that Zelaya might actually manage to somehow extend his stay in power, and they were determined to put a stop to that in whatever way necessary.