This is a bit of a complex question and some of this can only be speculate don but I will try to give a general idea. So the 1995 was the second independence referendum to take place, the first being in 1980. Now the other big event was the problems caused by the patriation of Canada's constitution in 1982. This was considered to be the last major step in truly establishing Canada as a separate country from Britain. While the constitution did pass in Canada, Quebec never approved it. There were two attempts to get Quebec to sign, the Meech lake Accord in 1987 and the Charletown Accords in 1992. Both of these ended in failure as the federal government and the various provinces couldn't come to an agreement. Despite losing the first time pretty badly there were many reason why the separatist movement felt they could win. The provincial legislature was controlled by the PQ( Parti Québécois), who had a majority government just as in the 1980 election. For the first time however there was a pro-separatist party in federal politics. The Bloc Québécois had been formed in 1991 and ran for election in the 1993 election. The Bloc did well and manged to win 54 of the 295 seats in Parliament. This was enough seats for them to become the official opposition. The separatists felt that the climate was as good as could be to hold a referendum. In retrospect it most likely was, the No side only barley won with 50.58% of the vote.

What would have happened in the case of yes is unclear mostly because the various people involved had no consensus on what the referendum meant. A large part of this was because the question on the ballot was considered to be vague. What can be said is that no party involved believed that a Yes vote would immediately make Quebec an independent country. The separatists believed it would force the federal government to open negotiations on separation or give them the support they needed to declare independence if the government refused. The federal government was less clear on whether it actually considered itself bound to recognize the results( the referendum was run at the provincial level). As a result federal preparations for a Yes victory were more involved with downplaying the results and getting Quebec to stay by offering major reforms. It is however quite likely that a Yes victory would have led to a serious discussion about how Quebec would separate both legally and logistically.

Is another referendum going to happen? Not likely anytime soon. Separatists are no longer nearly as powerful as they were. The Bloc as of the 2011 federal election is down to 2 seats. The PQ had a minority government but lost to the liberals last year. There have been no serious calls for another referendum since the last one. Support for separation has not been higher then 50% since 1995. A more recent poll shows only 1 in 5 Quebecois believe that the province will ever separate.