From the Departments of Francophilia and Reviving Interest in Antiquity, here is a translation of an article (Un amphithéâtre à Aix-en-Provence?, May 26 [now in subscription-only archives]) in Le Figaro about another archeological discovery in southern France:
To no one's surprise, the municipal team of archeologists in Aix-en-Provence have just unearthed nine ancient seat-rows (gradus) in excellent condition, belonging to a theatrical edifice that can only be the theater or amphitheater—until now unknown—of the Roman town of Aquae Sextius. This discovery should allow the community, which has wanted to create a public space, to design a "park of ruins" [on the site].Agence France-Presse broke the story (Un édifice de spectacle antique mis au jour à Aix-en-Provence [An ancient theatrical building discovered in Aix-en-Provence], carried here by Voila.fr [link no longer good]) on May 18. Another interesting article on the find is Aix-en-Provence: découverte majeure [Aix-en-Provence: major discovery] (May 19, France 2), with a video of the site from their May 19 news broadcast. It was related in that item that the site was discovered as a result of preliminary digging for a public park.
Located in a public area, formerly the property of the Sisters of the Holy Sacrament, the site of 3.5 hectares [8.65 acres] lies to the west, on the outside of the old city but within the Roman fortification, of which another section has also been found during this dig. Archeologists, under the leadership of Nuria Nin, have dug out a trench 100 meters [328 feet] in length and 5 meters [16.4 feet] wide. Besides the seat-rows, an interior corridor and a part of the interior space (cavea) have also been discovered. However, the curviture of the seat-rows is not enough to determine if the building was semicircular (theater) or oval (amphitheater).
Aix, the oldest of the Roman cities in the Narbonne region because it was built in 122 B.C., would logically have had at least some sort of theatrical building. Arles, Nîmes, and Fréjus, built subsequently, all have a theater larger than 89 meters [292 feet] in diameter and an amphitheater exceeding 110 meters [361 feet]. If the city's request for further digging is accepted by the Ministry of Culture, researchers will surely be able to determine the building's function. Whatever it was, this is already a major discovery for the city of Aix.
Now that most of the links in this article are no longer active, the best place for information is the site of the Mairie d'Aix-en-Provence, which has some pictures available.