Yes, there are courts.
Here is a <a href="http://www.wdwinfo.com/resortmaps/okwmap.jpg">map of OKW.</a>
The courts are 1st come-first served, but you can check (and should check) at Hank's Rent-N-Return for details. Racquiets are available there also- not sure about any fees.
The courts are next to the Main Pool and building 34. The ones near #34 are seldom used.
Enjoy!