I'm convinced, after seeing what the NYCC exclusive Star Trek Hallmark ornament did on the secondary market, that the Star Trek community is starved for collectibles. I don't think anyone felt the last line of action figures really were up to snuff. The playsets weren't terrible, and I actually liked the idea of the bridge, but when you can't deliver wave 2 and thus never be able to complete your stations, it's a real loser.
I think Lego sells no matter what. However, I don't know what the license for that costs so maybe Lego doesn't feel like paying out for it. Or, since they have Star Wars and their own Space section of City, they don't feel they need it.
I don't know if I'd buy into a Lego line of Trek but I'm interested to see what they do with KRE-O. The Battleship stuff looks cool so the ST stuff may work as well. But, if Hasbro ever got the ST license and gave it the full Star Wars type treatment in 3.75" scale, it would be hard for me not to buy it.