Though I support the idea that wealthy people should pay high taxes, perhaps even higher taxes than they do now, I think it's also worth noting that the US already gets 70% of all its taxes from the top 10%[1].
As long as we're keeping capitalism, I don't buy the argument that simply being rich is wrong. I'm also fairly skeptical of set limits on income, as setting those limits is very hard. What goes into it? How much money per year is the limit of a "Just" income? I don't think those questions have a definitive answer.
I think repealing the bush tax cuts is a good idea. I think we should keep the estate tax. I think the "buffet rule" isn't bad, but it's no solution. I just wonder when people will say it's enough. Rich people pay less tax today than they did a decade ago - but they're making massively more money as well. If we add all those taxes, and there's still a massive income imbalance, what then?
I think it's in everyone's interest to live in an equal society, for reasons that I don't want to get into right here. However, I'm dubious that can be achieved through targeting one social class or another. It seems like the American right is targeting the poor, while the left is targeting the wealthy. Everyone feels like a victim and just wants to keep what they have now. What a crappy situation.
Edit: I missed some words.
[1] http://www.taxfoundation.org/news/show/250.html#table6