If they made Outlaw spec have an "off-hand pistol" option I'd be ALL for it and would probably come back to WoW.
They could still have dual wield be an option, where you can have your dual swords, dual axes etc.
But they should also have a sword and off-hand pistol option.
It wouldn't be too hard to code, all you'd need really is to have certain attacks have two calls.
ie:
Sinister Strike: (with 1h Weapon in off-hand) does this
or
Sinister Strike: (with Piston in off-hand) does this and provides a different animation.
It could keep the attacks similar so we don't have to mess with our bars but each attack would be different but it would also add diversity.
Then instead of 'throwing daggers' when people are trying to get away, we'd just shoot them with the off-hand(if they were in range).
Not to mention they already have a "dual wielding" pistol spec in the game.
Lord Godfrey in Shadowfang Keep uses it. So it's nothing that they couldn't implement.
But I don't ask for dual wielding pistols as a Rogue, but a 1H + off-hand pistol option is something I would adore, especially if it could add certain combos to it to change up the style a bit.
For instance, you could hybrid the pistol 5 point combo attack with a 'cloak and dagger' like mechanic which would make you a little more mobile and get distance, not as mobile as sub, but enough to make it feel different if you're dual wielding or using 1h + pistol.
I can't go too into detail as I've been away from the game for a while but it's something I'd love to theorycraft one day.
Anyway, yes, one hand sword + off hand pistol should definitely be an option. As well as the classic dual wielding of course.
Like I said, they have double pistol spec in the game which Lord Godfrey uses, so they COULD implement that but I doubt they would do that. 1h + Pistol in off hand would be enough for me tbh.