New banknotes as from August 2013
 

New design Moroccan bank notes are to be issued later this week, see Banknote News

Unlike the previous design notes that also included images of Mohammed V and Hassan II, the new notes only bear the image of Mohammed VI.

I don't know how long the previous notes will remain in circulation, probably several months at least. I would then imagine you would need to exchange them at a bank.

yes, encountered the new 25dm note on my last days