As from 1st September, a TV Licence will be needed to use iPlayer to view BBC programmes.

S4C and BBC Radio are not included.

According to "techradar", here,
"  The BBC has no immediate plans to password protect iPlayer, meaning that you will still technically be able to access the service without a license.

The corporation has confirmed however that it is keeping its options open with regards to requiring a TV license number be provided by those wishing to access iPlayer, it just currently has no plans to implement the requirement. "

Another report may be found here, in "a516digital".