Let's suppose we have a subversion repository which looks like
/original/0.1
/original/0.2
/variantA/trunk
/variantA/branches/who/branch_for_xxx
/variantA/branches/she/branch_for_yyy
/variantB/trunk
/variantB/branches/who/branch_for_zzz
(... 30 or 40 alike)
where variantA and variantB are forks of the original software.
I am looking for a method for migrating this repository into a distributed version control system: a method
If you consider Git as a possible DVCS candidate, the ruby script svn2git does what you need.
More details in the question: Cloning a Non-Standard Svn Repository with Git-Svn