Nice posting on a basic definition of blended learning with examples of approaches including within Second Life:

In the strictest sense, blended learning is when an instructor combines two methods of delivery of instruction. However, this term most often applies to the use of technology on instruction.

Over the last few years the use of online/ virtual technologies for learning, teaching and assessment has gradually expanded. Serious Games, of course, are often part of the “blending” process.

Read full post at Future-Making Serious Games.