The kids club at WL is called the Cubs Den. We stay at WL often and stopped by to see it one day. My kids are dying to try it out. There is a big screen TV, DVD, VCR, games, activities, puzzles, crafts and a bunch of other kids. I wouldn't plan on leaving them for long, perhaps only long enough for a dinner one night.
I think that the poster above really was unfair in her comments. Vacation is for the family, and even mom and dad are entitled to a bit of time alone. While I wouldn't leave the kids there for a full day (and why would I if we're at WDW?) but for one dinner, why not?
I'm assuming since your dd is in daycare, you're a working mom too. My younger son (5 in July) is a full time daycare kid and my older son (now 9) was too. I also felt bad when we vacationed and thought about putting them in a kid club (after all, I didn't see them all day during the week) but then I realized that many of these kids clubs are designed to entertain and the kids love them (they are not just holding places until you come back). If you read the stories on the cruise board, you'll see so many kids want to go to the clubs to hang with kids their age, do activities, see movies, have fun.
I think that the price is something like $10/hour but you can check when you get to the hotel. Maybe stop by the den, take a look, ask dd if she thinks she might like to try it one evening while you and dad have dinner. If so, then go ahead. Don't let anyone make you feel guilty for wanting an evening with your husband.