>>
>> Would you mind pointing me to the configurations of OB 2.0 and MC 2.1? It would be interesting to look at an example in context.


You can also take a look on the project that was created to host the
configurations for several packages already:

MCHttpRepository
        location: 'http://www.squeaksource.com/MetacelloRepository'
        user: ''
        password: ''

there are few projects right now because the project was started a
couple of days ago.
Also, the configurations are being refined everyday but you can see
working examples of using
metacello.

Cheers,
Miguel Cobá
http://miguel.leugim.com.mx