2. Islamic State now exists on borrowed time. The biggest city they control is Mosul, and it's under siege by Iraq/US forces. Islamic State is the defacto force in large areas of eastern Syria, but only towns and cities are defensible there. Expect Islamic State to be driven back and eventually lose control of all its current territory in Syria. IS will either abandon the populated areas it controls, or they will suffer the same fate as Aleppo. One wild card in its hand is it's control over the dams on the Euphrates River. If IS went berserk, the destruction they could inflict would be on a nuclear scale.

3. Russia wants what it always wanted: a stable ally in the Middle East, and its naval base at Tartus. They would've intervened sooner in Syria, but the US and its NATO allies used conflict in Ukraine to keep Russia close to home.

4. Everybody forgets to consider the Kurds. They are likely to reach an accord with Assad for portions of northern Syria. This will infuriate Turkey.