Personally I like the levelable weapon system and would rather not see any levelable artifacts in the game at all. Making crafted weapons and armor obsolete makes the game heavily biased toward more powerful groups and leaves newer players struggling to keep up, forced to join a guild, or simply unable to compete. Crafting had been a huge part of Ultima Online, and the introduction of artifacts nearly killed smithing altogether.
Levelable weapons changed that and made smithing a viable career again. Levelable armor would help a great deal in that respect, but artifacts make armorcrafting almost pointless as it is. Adding more artifacts just compounds this problem as I see it, and making them levelable would only serve to push the balance back toward combat and farming and leave crafters once again with a severely limited skillset option.
We should remember that this is a game and that crafting was originally a huge part of it. It should be a major part, but as it is, smithing is being pushed back into obscurity as it was on OSI. If you want to focus on combat, good for you, but if you want be a crafter then be prepared to have a role limited to making pretty stuff to complement the Godly crap you dredge up from a dungeon,. Or worse, the stuff you get from just walking around killing random mobs.
We have custom ores, custom logs, custom leather, and all of it will be utterly pointless if you add leveling to artifacts.