None of these so-called "communist parties" or groups will ever get the revolution they want. They're too obsessed with ideological control, with making sure the five or six people they can find who have "true" beliefs will stay that way. Such entities make more sense as reading groups than as political groups.
Nobody will get very far searching for ideological conformity by trolling the crowd of freethinkers.
Look, I may be interested in all the ideologies of these various groups, but in an intellectual, not a political sense. Politics is about power, not belief.
Let me turn this debate around by casting it in another, more revolutionary, mold.
There will be a revolution. Didn't Marx say somewhere that capitalism can only maintain itself by continually revolutionizing the mode of production? The question at hand is not about whether there will be a revolution, but about what it will be like. The idea of a "worker's revolution" is empty. It could be anything.
So what will the revolution entail? Well, the working class will make the revolution, but working-class revolt is not a sufficient condition for an anticapitalist revolution. The evidence for this is littered throughout the history of the various Internationals.
Capitalism is doomed, not because some dramatic revolt will put an end to it, but because its continual operation will run up against the carrying capacity of the planet. The natural world, which Marx claimed as the origin of all values, can only stand so much capitalist revolutionizing before it starts to belch up natural disasters of an increasing magnitude. The '03 heatwave in Europe and Hurricane Katrina were only the beginning. Give the Hubbert peak and the accumulating greenhouse effect a few more years and something really radical will happen.
The form of the revolution itself is not entirely clear from this distance. It probably won't be accompanied by a massive trade union strike. It will definitely be accompanied by the demand of a global sustainable society. It will not result in an increase in human productive power. Intellectual rumination upon the form of the revolution had now best be preoccupied with how to create a global sustainable society, a society that can achieve stability without massive dieoff, because everything else is disaster. The intelligentsia's best slogan would be: ecosocialism or barbarism. Their optimal starting point is John Bellamy Foster's article Organizing Ecological Revolution.
The revolution will probably be accomplished by believers in direct action, rather than those who wait upon the votes of a majority before doing anything real. Today, debate is unfortunately entangled in making action conform to belief, a process which depoliticizes action. What makes action effective is not belief, but rather the way in which the various actors are co-ordinated to produce an end-result. All labor is social labor. Sure, the Greens could win election to bourgeois democracy and achieve little, but that's because Green electoral victory hasn't (yet) been accompanied by Green revolution, not because there's something inherently "social-democratic" about being Green. The Green Party is the only party I know of that recognizes (or once recognized) the need for both movement and party.
The fact that action is made effective by the proper co-ordination of actors means that people with imperfect ideologies can be effective in subverting the status quo, like for instance Ralph Nader or the Green Party. The US Greens, unfortunately, are not effectively co-ordinated to resist the bum's rush of the "Two-Party System." But I don't think of this as insuperable. The Greens are the most efficacious third party because their (de facto) demand for a global sustainable society addresses the current situation better than any other party.
The various communist and socialist parties, on the other hand, appear to have an understanding of the trajectory of history that is stuck in the past. It's not that Marx, Engels, Lenin and Trotsky are irrelevant to a discussion of theory -- they indeed are relevant -- rather, it's that political parties that believe in said figures insist upon repeating the history of 1848 or 1917. Why should we expect these parties to do anything of value? My eggs are in the Green Party basket, and they're probably staying there until a genuine ecosocialist party can be formed that can attract a mass base.