The current exhibition, A Cardinal's Dream,reassembles part of Ferdinando's collection to celebrate the restoration of the exterior of the Villa (interior restorations and the archeological excavation in front of the interior loggia continue). The works on display are certainly splendid, among them, to mention just three of many: a) The Sleeping Ariadne (long misidentified as Cleopatra because of the snake around her arm), which was and remains one of the most famous pieces of garden statuary ever made; b) Mercury, by Giambologna, (image at http://www.kfki.hu/~arthp/html/g/giovanni/bologna/mercure1.html) which graced the loggia fountain in the Cardinal's time, and which is the image that everyone has of Mercury, and c) the ancient statuary group of Niobe and Her Children, considered by many to be the greatest archeological statuary find of the last millennium, usually on display in its own gallery at the Uffizi in Florence.
Also included in the price of the ticket (IL16,000) is a guided tour of the Cardinal's top floor apartment with an extended stop to view the decorated loggia. Most of the Villa, which still houses the Academie and residence areas for the faculty and fellows, is closed to the public, and the huge gardens to the left and right of the piazza garden, in front of the loggia, are also not open. (It is not, however, impossible for a single person to slip away from the guide either inside the villa or at the loggia stop.)
Tape machine (IL6000) and live guides (free) of the "Dream" exhibition, which, unfortunately, are available only in Italian, are very good and every work on display is extensively explained. Exhibition guide books and small brochures are available in French, Italian, and English. The display areas are well lit and try to duplicate the Cardinal's own disposition of the works. The site is definitely not wheel-chair accessible -- many steps and stairways.
Internet links are mostly in French and Italian -- no surprise:
http://www.iskl.edu.my/Web/French/16/ -- French text and some good pictures
http://www.geocities.com/Paris/LeftBank/7798/Vasi/Vasi188.html -- Good pictures of the exterior and the Loggia
http://mistral.culture.fr/culture/sedocum/afrome-b.htm -- French text and pictures
http://www.arca.net/mall/romanelli/bronzi16.htm -- Order on-line your own full size copy of the Giambologna Mercury in bronze
http://www.geocities.com/Paris/Arc/5319/roma-c10.html -- The dent in the front door -- Swedish Queen Christina fires a cannon at the Villa Medici