From the essential LVA blog: www.lasvegasadvisor.com/whatsnews.cfm#8128

"June 10, 2010 Wynn Introduces Resort Fees: We heard a rumor and just received confirmation from an apologetic concierge that as of today, Wynn and Encore have introduced a $20/night resort fee.

The person with whom we spoke said that it didn't actually cover any amenities, like Internet service, but was just an additional $20/night fee."