As it says on the tin: what happens next? Caesar was currently planning a war against the empire of Parthia, so if he managed to get it underway, could he possibly win and expand Romes territory into the Euphrates and Tigris? ( given Romes future record on this though, its doubly it would last long.)
What about Octavian-would he still be heir? And what of Mark Antony and Brutus?
All ideas are welcome!