It would be interesting for us to be able to create virtual reality beings with their own free will and sentience, but also quite dangerous.
Think about other fictional portrayals of such beings; in Capcom's Mega Man Battle Network series Net Navis are virtual beings that can think and feel for their own. Some are good, others are evil. Evil Net Navis often go so far as to manipulate innocent people into their cause. Capcom did the same portrayal of artificial sentient beings in Megaman X, but leading to a nightmarish 22nd century where a robot dictator wants to exterminate mankind so that Earth is a robot's paradise.
Tron's sequel, Tron: Legacy, gives use the same idea as Megaman with regards to what I just mentioned. If virtual beings with their own free will and consciousness are created, they will have the same problems as our own society (war, genocide, murder, etc.).
Alas, I'm not a computer programmer, nor have I heard of any attempts at making sentient computer programs, but I believe it would take a lot of hard work and financial coverage to create them.