I read that neither the Venetian nor the Palazzo will charge, nor will Treasure Island. Also, the Station casinos around town don't charge. There are some others but I can't remember which ones.
I got this email today about a way to avoid paying for parking at the MGM properties:
Here's Your Free Parking Pass
Complimentary parking for Nevada residents will end on December 29, 2016, but you can continue to enjoy free self-parking at all our Las Vegas resorts.
JoinM life Rewards today, and then apply for the no annual fee2 M life Rewards Mastercard. Once your application has been approved, free self-parking is once again yours!
In addition to free self-parking at all our Las Vegas resorts, the M life Rewards Mastercard also gets you:
• Automatic Upgrade to M life Rewards Pearl Status1
• Priority Hotel Check-In at M life Rewards Destinations
• Buffet Line Pass at Las Vegas Resorts
NO ANNUAL FEE2
I would assume that offer would apply to anyone, not just Nevada residents.