As it happens in any war, before settlement, there will an invrease in violence.
Probably we will see a Assad assault backed by Russian and Ira/Iraq against a rebel army backed by the US, Jordan and the Gulf States. Turkey and factions within Saudis will be do double gaming (supporting rebels and IS).
Also there will be a rebel counter offensive.
IS will be always dangerous but for the first time it is really under pressure.
Israel will keep taking care of the more critical (to Israel) bits.
The big issue is that it looks like a lot of monkeys with big sticks in avery confined space. I saw a radar map of North Syria…really US and Russian fighter jets fly at about 25 km of distance from each other. The chance of errors are quite unique. Also in front of Lebanon there are quite a few warships from all sides (including China). Quite a lot of firepower. Better they coordinate well!