I think this is something that is really needed in the game. Weapons that can only be created (from scratch) by using tradeskills would ONLY be a good thing. It would accomplish a large number of things:
1) HUGE money sink to help fix the economy; tradeskill items and tools cost a lot of money, if you added a few items that would be required for these weapons that cost a lot of money, then people would be forced to give money back to the shops in order ot make the wepons
2) It would be a way for people without unlimited time to camp mobs a way to get really cool items. Most people playing AO do not have the time to camp certain mobs for hours, sometimes days, or even weeks on end just so they can get some special loot. As it is currently, these mobs are currently camped by a select group of people who are hoarding these items and selling them either on eBay or selling them for disgusting amounts of credits in game. Tradeskill only weapons would be open for creation to anyone who has the tradeskills necessary.
3) finally really give people a reason to put IP into tradeskills. Currently most people put IP into tradeskills because they are required by some NON-tradeskill items. These include scope, trimmers, and even some armors and weapons. Have you ever seen someone shouting "building weapons for cash"? Know anyone with a high chemistry skill?
I think making weapons and other items is fun, but there really currently isn't any reason to do it. The only items that are actually worth it to make are Grid Armor nano crystals. Why? Because they are tradeskill only. You really need to add more of these things, Funcom, I think many people would agree, it would add a lot to the game.