If your room sleeps 4, you will get one of each for each person. We've had CMs tell us that there are extra towels at the pools if we need them, but I've heard that the practice is really frowned upon.
That's correct - you'll get a set for 4. 1 bath towel,hand towel,wash cloth for each person and then a bath mat. You can use the washer & dryers free of charge at the resort though (either bring detergent with ~ like Tide tablets or you can pick up a box for 1 load's worth of Tide in the gift shops for around $1 each) or you can also purchase an extra towel pack for $6 (less than the price of 1 pool bar drink when you think about it )
We asked housekeeping for extra towels when 7 of us checked into a 2 bdrm at OKW on our last trip. The nice housekeeping lady turned up in about 10 minutes with 2 HUGE stacks of towels - more than just an extra set for each bathroom.
Even with a 3 yr. old, we came out ahead in the towel department. An extra pack of towels is supposed to be charged $6, but we didn't see a charge for them after checkout.
No, if you are getting a studio, you will have 4 of everything, and they won't be replenished during your short stay. If you need extra, you can get an extra set (4 of everything) for $6 from housekeeping. We usually always get an extra set from housekeeping when staying in a studio. Its only $6, in the course of a Disney Vacation this is pretty much a bargain!!