Welcome, Evan! Many mods have been developed for this platform, and more are in the pipeline. Like Robert said, ideas are being tossed around on the IC, nothing conrete yet. Transmission related mods take the game to a whole new level of investment in time & money. The best thing you can do to date is keep the fluids (trans, PTU, RDU) changed out regularly if you run your SHO hard. The AWD system isn't full-time, primarily being FWD in character, and pulling in the RWD portion as needed for traction & stability.
In production performance mods to date: tunes, catback exhaust, downpipes (catted & catless), exhaust cutouts, hot pipes, bigger turbos, methanol systems, coilovers, and big brake kits. If you are up to it, you can add in 4DRHTRD's aux fuel system setup for even more hp. 4DR (Mike) can order you quite a bit of this stuff directly at competitive prices, head on over to
http://www.ecoboostpowerparts.com.
Head over to the HOW-TO section of the forum to get a feel for what's going on in the EB/SHO world. Time well spent.