If the situation in early 80's Poland turned into an outright rebellion, I think that the Soviets would either have to risk invading or allow the communist government to fall. Jaruzelski managed to stop this from happening but I think it was definitely possible and that if it did occur, it could be a much more violent and dangerous situation for the Soviets than in Czechoslovakia and Hungary.
If this uprising occurs, it is very difficult to see the rest of the people of the Eastern block countries stay willingly within the warsaw let alone join together to crush reimpose communism on Poland. I think this would be especially true of East Germany and Czechoslovakia. This, in turn, could destabilize the USSR and send it into a situation like that in 1988-1991. On the other hand, if the USSR does not invade and holds together, it might be able to get rid of the Eastern bloc in an organized manner and gain a degree of stability in the long run, especially if it can get NATO to limit its Eastward expansion.