Appearance-wise, you can simply apply those attributes such as curved and spiked and whatnot and it will show up in the game as such. For example, that would mean everyone\'s sword have a picked attribute such as regular, spiked, OR something else. This appearance is already integrated in the game rather than processed and pop up dynamically in-game as I think some people had in mind.
The big problem is making the implementatin design, coding, artwork in the first place. I recommend this restriction -- I don\'t think the player should have rights to making the artwork. It should be restricted to only what the game has already so that everyone can have it without needing weekly patched..... OR if you want, only you can see your MODDED appearance, but not everyone else. This might give rise to problems such as incompatibility though.... and more coding.
And Whemy, I don\'t think you know what kind of work goes into make a simple patch.... allow me to inroduce to you the Unified Process... it\'s basically 4 phases: inception, elaboration, construction, transisition. These 4 phases are applied in iterations for independent subsets of the overall product. A patch probably has to go through many of these iterations, which entails things like lotsa of design, documentation, testing, and coding.
Of course, this is dependent on the level of work associated to the patch. If this is a small content patch that just adds just a bunch of easily scripted missions to the game, then you probably need only a tiny iteration.
Then again, you have the example with Blizzard, a company that worked on a diabloii patch for 3 years and still hasn\'t released it yet... it\'s hopefully going through its last testing phase.