This information is important for all people interested in visting Croatia and neighbouring countries, especially low budget travelers and backpackers since they are extremely reliant on passanger rail services. As of December this year, cross-border train travel to and from Croatia is about to get a whole lot more difficult as Croatian Railways has announced hat it is to cut 44 out of 56 daily international services, and even two of the remaining ones would run in summer only. You can read the announcement here:

Announcement by Croatian Railways (Croatian)
Announcement translated with Google Translate (English) 

In short there will be only one train daily from Vienna to Zagreb, probably two trains from Belgrade, Sarajevowill only be connected to Zagreb by buses. Perhaps the worst situation will be for travelers from Budapest which won't be connected at all to Zagreb during the low season since there are no direct or indirect bus connections. Anyway, with the help of "World Carfree Network" people in Croatia are trying to oppose this decision by signing a petition and  are hopeful that government and Croatian Railroads will change their mind and revoke their decision since it might be hazardous for the future of Croatia as a tourist country. If government doesen't change it's mind, Croatia will be left with six international railway lines altogether. Please revisit this page ocassionally, because further developments will probably be posted here