Of course, there is a slight continuity problem with a sequel to Gladiator -- namely that the movie's main characters / big stars all murdered each other in the last five minutes. So instead of continuing the very much closed story of Maximus, the sequel will jump forward in time to focus on the heroic story of Lucius. You remember Lucius? The awkward kid who couldn't read social cues and blankly stared into the middle distance while his emperor uncle tried to bang his mom? Apparently, adult Lucius has decided to model his life on that guy he briefly met, whose family was brutally murdered and who bled out in an arena, and become a gladiator. Sounds exactly like the kind of character deserving of whichever Hemsworth brother's abs they'll use to fill out the role.
Not that Gladiator II can't turn into an amazing movie; it's just that it'll never match the sheer awesomeness of the Gladiator sequel that never was. Right after the original raided both the box office and the Oscars, plenty of people wanted to make a follow-up. That included Crowe, despite his character being as dead as an Iron Age door nail. To get around that, he contacted, of all people, singer-songwriter Nick Cave, and told him to write a spec Gladiator sequel in which Maximus was still around somehow. Cave (who's also a very talented writer) took this as a license to get weird with it.