I'll have a go:
1. There will be no obvious/runaway winner (during voting, the top songs will keep changing places), unlike previous years,
2. There will be technical difficulties for Sweden (assuming they do the video backdrop thing) during either the Jury or Main performance, and controversy surrounding whether they get a second chance
3. Russia might get booed (again) but there's no way we'll hear it this time,
4. The UK entry will surprise everybody (hell, it getting any points would surprise some),
5. Australia will complete last in the final.