Now that players are starting to grind up some real rep in Outland, we're definitely seeing more and more Aldor vs. Scryer sentiments-- Death to Scryers, by the way, because I'm Aldor to the Core(TM). And at least a few players have already suggested that the Aldor/Scryer rivalry might eventually lead to something new in PvP: an Aldor vs. Scryer battleground that finally mixes up the factions on either side, and lets Alliance play alongside Horde and vice versa.
Paladinsucks, in fact, says why wait? Aldor and Scryer battlegrounds would be cool, but there's a lot of benefit in making the old battlegrounds "faction-neutral" as well. All you'd have to do, PS postulates, is employ the Old Hillsbrad trick of costuming (when you enter Old Hillsbrad in the Caverns of Time, your character temporarily becomes Human), and boom, you've got a whole new world of PvP. If you were Horde, you'd sometimes be defending Warsong, and sometimes Silverwing. In AB, some Alliance players, playing as Horde, would guard the Farm. Strategies would be more complex, and, in perhaps the most intriguing benefit, queue times would cut in half.
There are drawbacks, though, too-- the fun of playing Horde is hating the Alliance, and vice versa, and if you had the enemy on your side, things just wouldn't be the same. PS doesn't offer any suggestions as to how you decide who plays what side, too-- is it random, or do people get to choose their "faction"? (Because if they chose, who would choose to play as Alliance in AV?) I would love to see some faction-neutral PvP in the game (besides the Arenas, which are every man for himself), but getting a new Aldor/Scryer battleground, in which I can play for my faction on my own character, seems a much better solution than completely revamping the old ones.