Capcom have this habit of putting certain main characters after each other in their game... RE1 -> Jill/Chris, RE2 -> Claire/Leon/Ada, RE3 -> Jill/Carlos, RE4 -> Leon/Ada, RE5 -> Chris/Sheva
But it may not be sure that Leon will be the main character in Resident Evil 6. I doubt Resident Evil: Code Veronica X will be the only "spin-off", so he may pop up in one of those. Then we have the possible re-make of Resident Evil 2 (the creators have even said that re-making that game sounds interesting when they're done with RE5), where Leon will star alongside with Claire in Raccoon City again.
If they re-make RE2, then I find it very unlikely that they will use the same character twice in a row (Leon in re-make AND RE6). So, the day Resident Evil 6 is confirmed, who do you think will be the main characters? Rebecca? Billy? Jill? (Maybe Jill is dead, maybe not. No one have played the game, so no one knows.) Carlos? Hunk? Barry? Or a new character?
I hope this game ends with a bang like Wesker and Chris both dying, then Resident Evil 6 has Claire and Jill taking down the remnants of Tri-cell for good, maybe in Tokyo, so we could kill plenty of Asians... not to mention the change of scenery Tokyo would provide compared to previous games... Leon could even cameo as backup. It would be such a good ending to the series. Bright lights, congested alleys, masses of asian zombies, players heading to a Tri-cell facility in the middle of the city, and ending it all with a big explosion that takes out half of Tokyo, and all of Tri-cell.
Two main characters in an RE= female? Not ever going to happen. Don't count on ever seeing a female main character again in the series, actually. The closest we'll get is either back up co-op Sheva-style, or Ada-style subchapters.
Life is not about second chances. It is about a little mouse and his voyage to an exciting new land. That, my friend, is what life is.
the main character of RE6 will be HUNK. u will start off the game as him doing covert operations for umbrella (or whatever is left) and mid way through it all he will gain a conscience and turn on umbrella.