As from June of this year (I think) the CPL will no longer exist. There will only be as I understand it PPL or ATPL and that's your lot.
Once completing an ATPL course you are issued with a Frozen ATPL until you gain 1500hrs allowing you to do F/O duties only, then it gets "thawed out" after 1500hrs and you can now act as Captain should you be lucky enough.
Apart from other goodies attatched to the ATPL as mentioned above there are age limits which differ from the CPL but anyway, no more CPL soon so it's not even worth thinking about.
Hope this helps, good luck.