1.- SL is full Language institutes. I think this is good if you want to take language courses online, because it permits to practice oral skills in save environment. The problem is in the majority of them, you must pay. I don't know if this is good or bad.
2.- SL is lack resources for ESL/EFL. I think this is a bad point. Most of the resources in second life are in English, so you need some training in this language first in order to really enjoy it. I think SL could be the major center for practice English if EFL/ESL teacher use it.
After this little reflection about SL and ESL/EFL, here are my places.
Open Community to practice English through voice tool. Chat mode is not allowed. There is always a person to talk.
Free Community that permit you to practice for English, French and German in all levels. They Have a calendar with all the activities.
SL English language Institute with classes in different levels. Suscription is needed.
Free place to practice english language. Only text chat.
Language Institute in the sky. Subcription required.
Spanish institute with Mexican Culture Orientation. Subcription required.
Institute that offer classes in different languages in groups. Suscription required.
Organazation which works in preserve language and culture from Native Americans.
SL place full of resources fro ESL/EFL Teacher. Some of them are not free.
This academy offer classes in French, Spanish, Italian, Japanese and German. All of them are for free!