check out Hausner, Jessop and Nielsen (eds.) 1995, Strategic Choice and Path Dependency in Post Socialism in the Transformation Process, Aldershot (UK) and Brookfiled (US): Edward Elgar. These authors essentially argue that i was not 'shock therapy' but institutional culture.
Poland started implementing elements of market economy (mostly trading between firms) in 1956, and so did Hungary. 1989 was not really a "transition" but stating the obvious - that central planning had substantially eroded and was repleced by semi-market mechanisms.
Russia was different, because no such attempts to introduce "market elements" were made and because of the sheer diversity of x-USSR versus Eastern European countries.
see also Bernard Chavance, 1994, The Transformation of the Communist System, Economic Reforms Since the 1950s, Boulder: Westview Press.
wojtek