To those saying Orwell wasn't a communist...
Well, it's tricky. Democratic socialist was probably the best term at the time, though it didn't then connote the lack of radicalism it does today (it used to simply mean socialism with a democratic process; now it kind of means socialism achieved through parliamentary means). The word socialism has never had a precise meaning, and its use has always differed between groups.
However, Orwell was a Marxist, which in my book makes him a communist. Don't confuse his overt opposition to and subversive deconstruction of Stalinism with anti-communism; you've heard of Rosa Luxemburg and Emma Goldman, right?
In 1984, his target was indeed totalitarianism itself, not a specific regime, but that didn't stop him referencing Stalinism in some parts, such as the scapegoating the Party engaged in directly paralleling Stalin's scapegoating of Trotsky. I fear some people didn't understand the book though if they don't see how it portrays a world where Stalinism, fascism and other totalitarian regimes have seized control of the whole planet, negotiating a constant war between each other to maintain their stranglehold, with little to no actual ideological difference. Note also Ingsoc, or English socialism, being the name of the party's official ideology: This is very similar to Mussolini's national syndicalism, Hitler's national socialism, and Stalin's socialism in one country. He saw the similarities between all these regimes, but also had a deep understanding of all of them, including their ideological and historical differences and how these changed in importance over time, which makes him a better critic than others such as Ayn Rand, who didn't really understand any of them.
I don't think Orwell ever criticised communism itself at all, but since most people in the western world today think of communism as totalitarian socialism, it's a common misunderstanding.
*Sorry for the absence of italics, couldn't get it to work on this device.