Are the keys in a multisig transaction output hashed? Pay to public key hash scripts hash the recipients public key for added security.

Is the same done with the public keys that make up part of a multisig script?

https://en.bitcoin.it/wiki/Script doesn't seem to indicate they are.
Typically, you will use P2SH (pay to script hash) for multisig transactions, which means the transaction output does not contain the full script (with full public keys), but instead a hash of that script - and the full script is revealed when spending. See BIP16 for more information.

When this is done, you get the same effect: the transaction output does not contain a public key directly.

Note that there is indeed a  small security benefit to this (it takes 2^160 steps in theory to reverse the hash function, while it takes 2^128 steps to find a private key for a given public key), but there are larger advantages (like the sender not needing to know the full script, and less data in the database of unspent transaction outputs that every full node maintains).