Oh, I'm not necessarily saying it shouldn't be included. :3 I'm just saying that it's not all that much better than steel for most purposes it would be used for in the game, if it is, in fact, any better at all, which I doubt for reasons covered in the previous links.
Better than (assuming wrought) iron? I'd say probably for armour, but not for mass weapons. For swords and other edged weapons, I'm leaning towards "no" since I think that wrought iron edges would be easier to sharpen and probably hold an edge for as long if not longer than any titanium alloy I've read about. Plus, added mass, though making the weapon slower, would lead to an increase in momentum transfer to the target which is very important for any weapon. Also... I have a feeling that titanium might not actually be better for maille... the only way to really substantiate that, though, is to find an actual test. I'm gonna search for that sometime... Maybe it might be better, though.
Also... if corrosion was in the game, then titanium could really shine!
So, I'm not against its inclusion, though I'm not sure I'd use it if I had abundant iron and the capacity to make good steel, given its properties are accurately modeled.