I'm not from Nokia, but I guess that Nokia is more likely to use the SIM card as the Secure Element (at least in Europe) as in the 6216.
The carriers won't widely deploy NFC handsets until the Secure Element is stored inside the SIM card, so I guess that Nokia will have to comply.
But that doesn't prevent Nokia from adding their own Secure Element, in which case they might be interested in using a secure technology that hasn't been broken, so it's still possible we'll see phones with internal Mifare Plus tags...