Rebel Minis have announced that the Spell Cards and Effects tokens for Mighty Armies are now available.
From their website:
Great News. The new Cards and Chits are in. These cards and chits will be included the official box sets. All the sets customers bought since the new release(that did not get cards) will receive a pack of cards and chits mailed to them.
We will also have the Card/Chit packs up on the site for $1.99 for those that would like them for their armies and have not bought box sets.