I've been going here for four years for school-related projects, but today I went with my aunt for one last trip before I leave Pittsburgh for good. I was happy to see several Chihuly pieces still on display (by far my favorite exhibit that they've ever done). Their current exhibition involves Gargoyles, and the mythical stone creatures either provided a nice contrast to the sweet flowers, or they blended well into the lush scenery. It was a nice homage to some of the gothic architecture in Pittsburgh.
Also, if you're in town soon, check out the agave plant in the cactus room. After taking a range of 10 to 70 years to grow, it's center has shot through the roof of the building -- a sign that it's now near the end of its life.
I would definitely recommend visiting Phipps if you're touring Pittsburgh. Museums are a dime a dozen, but this conservatory is something different. It's a perfect visit no matter the weather (and weather has a tendency to go wrong in Pittsburgh) and even the children's garden was captivating to me (I seriously spent twenty minutes walking around with a plastic elephant shaped watering can, looking for something to water).