question about new consumer offset management in 0.8.2

[Jason Rosenberg]

Hi,

For 0.8.2, one of the features listed is:
  - Kafka-based offset storage.

Is there documentation on this (I've heard discussion of it of course)?

Also, is it something that will be used by existing consumers when they
migrate up to 0.8.2?  What is the migration process?

Thanks,

Jason