#4 would be an AWESOME story. It would also be really hard to write since George Orwell set a higher bar than the 80's cartoon did. The fun part would be seeing how the humans (notably Spike and co., obviously) would be different or similar to their original selves in this alternate world, and how the government would react and/or adapt to this huge wrench in the works.

Considering how the book 1984 ended, there isn't much the Cybertronians could do to make it much /worse/.