I would like to see them do what Phoenix did with US Airways Center a few years ago. Their arena was built around the time of the ESA and they updated the exterior to give it a more urban look. They completed the renovation in 2003, dropped capacity from 19,023 to 18,444 (not that I support dropping capacity, just pointing it out) and built a glassed pavilion that interacted far better with the street than the old arena:
You can see the original arena and the expansion:
I would love for the north-east corner, by the TRAX stop, to construct something similar.