I'm actually reading the Item Familiar feat in UA right now an d heavily considering taking it with my current character. And I am pleasantly surprise that they use the term sapience instead of sentience, which are confused way too often.
And yes, thee are way too few options for intelligent weapons in the DMG. There should be at least twice as many, especially for the special purpose powers. Heck, there should be a simple mechanic for just allowing the use of a spell of a given level so many times per day or something.
I really hope there are more options in the Magic Item Compendium.