I like what they did with Shang Tsung. I won't be playing him, but it's awesome to see him around. However, there are way too many guest characters, but that's what I expect after MKX I guess.
Also, choosing SIndel and Nightwolf instead of more popular characters is kinda weird. I mean, I don't begrudge them their spots necessarily, but seeing four undeniably more popular characters rolled into Shang Tsung's special moves while other B-tier characters get a full slot kind of stings.