Gnome area has been up and running since closed beta started, I ran my gnome priest through there last week - it's a nice area and there's a battle with Mekkatorque, at the end the Dwarves throw a party and give you free beer lol.
I don't know if they've fixed it yet but currently gnomes start at the old site.. with the dwarves and so if you wanna do the gnome area you need to run yourself up to Gnomer which isn't too hard since Blizz put in that nice little path with no mobs.