Mail from Tawan:

1. Probably just Classic Sudokus.
2. Variants with missing clue elements.
3. A big round with all the basic variants.
4. A big sudoku jigsaw with 100 pieces!
5. Variants using arrows.
6. Variants with disguised, false, liar clues.
7. Coded variants.
8. Seems like another round with arrows - perhaps a bigger team round.
9. Dice themed, maybe 6x6's.
10. A large mixed-bag round.
11. Team round where each member contribute clues to a bigger puzzle at the end.
12. Matching rule sets to each grid.
13. Team round with limited communication. A no-speaking round?
14. If there had been no arrows up to this point, then surely they're going to fly here.
15. Linked puzzles laid out in a circle.
16. Sounds violent. Maybe a round of hard classics that needs bifurcation. Probably written by Ashish.
17. A sprint round with easy puzzles.
18. A round with bits of everything in previous rounds. Maybe a weakest link-style team round.