In Fallout 3 and New Vegas, you could repair them yourself fairly trivially, and they didn't degrade so quickly that you went through at least three per fight (forcing you to pause the game to select a new weapon each time). From what I've heard so far, even end game weapons have the durability of paper mache, and fixing it requires you to trek back to the nearest smith and pay to get it reforged. Seems like a fantastic way to completely ruin the flow of the game, if you ask me.