Yes, indeed it has.
In RL, I have high-functioning Autism (Asperger's) which affects my ability to socialize well. While that does not stop me from getting out and meeting people in the real world, I am often felt alienated because of my inability to recognize facial expressions and tones of voice, which often causes me to misunderstand things or respond the wrong way. A speech problem of mine also does not help.
In Second Life, however, people can communicate via writing. There are no expressions or tones of voice I have to try to understand; it is all emoted, which makes it much easier for me. ( /me smiles.) I also do not have to speak verbally, so it makes communication much faster and easier...for me at least. This has helped enable me to meet more people, build up genuine friendships, and have a blast roleplaying. Second Life helps provide me with a social life, albeit a virtual one, and I am enjoying it thoroughly...though, perhaps, a bit TOO much; I fear I might have become addicted to it now!