Hi Amy,
How exciting to be traveling with your best friend. I just did that last year and we had a blast! Yes Pleasure Island was recently closed and at this time it is unknown what the future plans of that location are. Hakuna Matata though-no worries- as there are still great places that you two can go to have a great time.
Most of the Disney resorts have lounges on property and you are welcome to visit any of them during your stay. Downtown Disney still has some great things going on late into the night. Marketplace shopping is open late and be sure to check out the Westside for bars, movie theatres and more. Depending what time in the evening you mean, Epcot's World Showcase is a great way to spend the evening and on certain nights of the week Epcot features Extra Magic Hours giving you an opportunity to stay and play later than usual. A fun activity for some, is to grab different drinks as you travel the world, otherwise known as the Epcot crawl.
For me and my BFF (best friend forever), our favorite nighttime hangout was Disney's Boardwalk. This resort is nestled along a water front area with a old fashioned Boardwalk stretching down the resort. While strolling down this walkway you will encounter free entertainment, unique shops and restaraunts, the ESPN bar and two night clubs, Atlantic Dance Hall and Jellyrolls. If you are looking for a briefing of the days sports (and I mean ALL sports) stop in ESPN. If dancing is your thing, then stroll down to the Atlantic Dance Hall. Our favorite is Jellyrolls, featuring two keyboardists dueling for your applause. For more information on all the Boardwalk has to offer visit
here.
Have a fantastic time!