To me, the Worgen thing makes perfect sense if you think about it... I mean, as someone said earlier, just because some members of a race decide to pick a side, doesn't make all members of that race aligned with that picked side, which concludes that the Steamwheedle Cartel will remain neutral, as just a few Goblins would see the profit in siding with the Horde.
As for the Worgen, I'd figure it would be something like this. As you may or may not know, the Worgen are said to come from another dimension, and as someone else already said, but most delightfully overlook, is that they carry the "Curse of the Worgen", which makes other creatures, such as Humans, turn into Worgen at night-time. (Go to Pyrewood Village south of Shadowfang, the people are Humans by day, Worgen by Night) Now, let's assume that this curse is what has caused the Kingdom of Gilneas to stay isolated and unheard from ever since the outbreak of the Third War. The gates of the Greymane Wall have never been opened since then, so noone outside knows what is going on inside. Maybe there's a civil war going on between Worgen Humans who have -retained- their free will (despite their physical form having been tainted forever), and the Worgen who are truly lost to the corrupting control of Archmage Arugal?
Despite me not playing WoW anymore for two years straight now, I always wanted to see what happened to the people of Gilneas, and hoping they'd be Worgen to add some much needed predatory instincts to take on those Horde milking machines : P
And it would make less sense to add Pandaren as they were made initially as a joke by Samwise during WCIII (though having been confirmed as a race later), and also you have that entire China thing going on about them..
Anyway, yeah, I want to see a Worgen race on Alliance.