Yes, it has been identified. IIRC, Napoleon was the first to send engineers out to find the various sites identified by Caesar in his Commentaries. Subsequent archaeology proved the site as Alesia.
It wasn't Napoleon, it was Napoleon the 3rd; and there has been discussion over the years, different proposed sites, I just didn't turn any of those proposals up using the search, and am pleased that anyone's interested, regardless.
wikipedia for the official site and wikipedia for Chaux-des-Crotenay, BBC article for Chaux-des-Crotenay, image search
The gubmint of France has an official location of the site, so if the site is found to be somewhere else, they've got an embarrassing huge-ass statue in the wrong place and on their hands. Something similar happened in Germany, a big statue commemorating the Varian disaster was built in the 19th century, and it's about sixty miles from the actual location of the battle.