Whether you're keen on Second Life (SL) or not, virtual worlds (VWs) are coming, and not just for entertainment or education. Elearnmag has an article on Another Life: Virtual Worlds as Tools for Learning which is well worth a read.
Reading stuff on SL generally requires you to sort out the sensible from the hype. This article is no exception, but it does have a number of sensible things to say:
We encourage you to examine this technology with fresh eyes and begin by asking what sensibilities it can bring to the learner that aren't found in traditional learning technology. So instead of asking "How do I build a virtual classroom?" we might ask, "What can this technology do that will enhance the learner's experience that my current learning technology portfolio cannot?"
In other worlds, if we were going to use SL for language learning (and I've got some serious doubts), we shouldn't just be seeking to replicate what we do in our face-to-face classrooms.
The article continues:
Major corporations are creating a lot of buzz around VWs but most of it is promotional. It's hip, and compared to alternatives, it's cheap. But it holds few answers to our questions about how to improve learning with VWs.
As with any other form of technology you might use in your classroom, if it helps your learners to learn more, and better, let's use it. If not, let's not.