Spooncraft

Currently Death Knights can self enchant their weapons with Runeforging, which works almost exactly as regular enchanting only without the materials and such.

Runeforge enchants do not stack with other weapon enchants. But in most cases the runeforge enchants are better, and they are certainly a lot cheaper. If you find yourself in a situation where an enchant from an enchanter seems superior, you are still able to do that. Furthermore, enchanters can still provide you with enchants for all your other slots. (src)

That’s the short version, here’s the long version with twice the amount of blue than you’re used to. That’s the thing I LOVE about Betas, the forums are FUCKING EXPLODING with feedback and discussion between developers, CMs, and testers all sharing information and next to NO trolling or bullshit arguments. If you know what you’re talking about and make a good enough point, it might just get changed in the game.

A weapon can only have a permanent enchant and a temporary enchant. This is a technical limitation, and honestly not one that is worth the cost to change (see below). The runeforge enchants simply cannot stack with Mongoose or other permanent enchants. They can stack with Frozen Rune Weapon or theoretically Windfury Weapon if there was a way to get that enchant on the weapon. (Windfury Totem is just a passive haste buff now, so it does stack.)

I think it’s fine if the runeforging enchants don’t stack with other permanent enchants because the runeforge enchants can be as powerful as they need to be. It’s okay if they are the best in their class — they are offered as a perk of the deathknight. The current ones already scale much better than current enchants. There are apparently some bugs with the runeforge enchants in your build — Crusader is supposed to be a 30% buff to Strength, and it could be much higher if that isn’t enough. We’ll look at getting something that fills the Mongoose niche too.

Characters with the Enchanting profession can still provide enchants for the various other pieces of death knight armor. And since Feral druid enchants will be much more meaningful, perhaps the enchanters won’t miss the death knight customers quite so much. (src)