This is a great question bjarz12 and is certainly an issue on this site. In my experience it has been up to the local property whether they make these fees mandatory or let you opt out. You can call them prior to your stay or you could take your chances at check-in time. I prefer the later because it's face to face and have never had to pay resort fees. Good luck and thanks for your post.
This is merb's response to a points earning question on Nov 18, 2013 12:47 PM (in response to bjarz12) bold added by me
Hey, I just noticed - it was to you - ha
So, I talked to the specialists, and this is what I learned: The resort fee is a tax-like fee and as such, they are not eligible for point earnings. Resort fees are equated to additional taxes that the resorts charge and are classified by each hotel differently. If the resort fees amenities are not "used," it can be refunded.
Here is what the last ruling on resort fees were - per the Marriott representative at the time;
Laura the Marriott representative answered on April 20, 2011 at 8:20 pm
For any reward redemption stay you may choose whether or not you wish to pay the resort fees for the additional amenities, opt out entirely, or opt out and pay a la carte. If you decide to pay the resort fee you may pay with points using an “instant redemption award” (for properties that support instant redemption), or you may pay cash.
So, like bpelican states, it's now, cut your best deal property by property. Remember, it's double or nothing - if you pay resort fees, you do not earn Rewards points. Best of luck.