Back in the early 80's I read a huge chunk of the three volumes by Kolakowski on Marxism, reviewed there by Judt, after Telos had two reviews of it. Brilliant critique by the former "revisionist" Marxist of the utopian dimensions of Marxist eschatology. (Cf. Stanley Moore, "Marx on the Choice between Socialism and Communism, " and Polish libertarian, A. Walicki, "Marxism and the Leap to the Kingdom of Freedom." Having read the Grove Press edition of his essays from the 50's and 60's [the only book ever to have been blurbed by both Sidney Hook and Tom Hayden], from the late 60's, in high school, I was eager to read them.)
Kolakowski's reply to E.P. Thompson's Open Letter, decrying his move towards what K. called, "conservative socialism, " (contained in the 2nd volume reviewed there by Judt) , here in the Socialist Register from the early 70's has some funny comebacks,
http://socialistregister.com/node/16
http://socialistregister.com/socialistregister.com/files/SR_1974_Kolakowski.pdf
Another review of the reissue of the Kolakowski (rather unwieldy, the original was in 3 vols, the new HB could kill someone dropped from 20 ft.) is in a recent issue of The American Interest, the spin off from The National Interest from the anti-neo-con Realists.
Judt volume I also recommend on the French Stalinist and fellow travelling intelligentsia of the 40's and 50's, "Past Imperfect: French Intellectuals, 1944-. 1956, " from Univ. of Ca. Press. Great read.