The very first MK boss, the first shapeshifter, the greatest human sorcerer (and maybe intellectual as well), the best-dressed warrior, and the only "grandpa" (together with Shujinko) who can still beat the hell out of anyone...- Shang Tsung. I always liked him really, both his personality and special moves, so much that I felt somewhat sorry when Liu Kang would manage to beat him. I never cared for his being a villain. His destiny was merciless towards him: first, he was cursed by his own gods to steal souls, then defeated by: 1)The Great Kung Lao 2)Liu Kang 3 times, 3) Quan Chi, 4)Raiden (with his suicidal blast). He more than deserved to climb nearest to the top of the pyramid in MK: A's intro.
However, I seriously fear he won't appear in the next MK. The reasons are various: Tsung has never had many fans, many hate him, he was given too many futile chances to defeat Liu Kang to have another try, he is considered a low-tier character, some even speculate he is a gay (whoever said that, please report me the arguments). Personally, I would feel kind of grief if he died in Armageddon. To me, he is one of the most accessible characters; I can choose Tsung in MK3, play the Master-row on the Very Hard level and defeat everyone in the row, from the first one to Kahn, as I did countless times... No new sorcerer could truly replace him; perhaps Quan Chi, but I don't know...Quan Chi's magic powers and charisma never looked so convincing. Anyway...

...Do you think Shang Tsung should return?

Just making the title more clear, as you're not asking if Shang will be back, but should he be back. Jerrod