It still seems a bit dead over there, but I think it is slowly improving. Best Friends Animal Society recently openend up an adoption center that is open Wed-Sat, not a huge traffic generator but I guess it does bring some people in that wouldn't have normally been there. They have a billboard across the street letting people know they are there.
Probably the most impactful new opening in the last month or so is Spark, it's a mens fashion store, used to be in Sugarhouse in the sugarhole, then moved to State next to Decades, now they have opened in the former Banana Republic location. They have some great prices on mens clothing and shoes, very metro fashion oriented. It would seem to be the best selection of banana hamocks in the city as well.
I too agree that it hasn't reached it's potential, which is what frustrates me about the gas station going in across the street. Hopefully the proposed residential, from several years back, across 5th South from Smith will happen soon. Trolley needs to become a more dense neighborhood, with more housing, creating a built in customer base for Trolley Square.