One benefit of having a separate crown corporation is that it allows the creation of a separate bank account that will be managed to the benefit of premium payers and benefit recipients, so that the rates can remain a bit more stable. Another advantage is that there will be additional predictability in the setting of the premium rate by having a clear set of guidelines for the crown corporation to set its premium rate going forward, as well as having premium rate payers benefit from any potential surplus that could arise in the future years.
On May 1st, 2008. See this statement in context.