L'Artisan has apparently ceased production on the 50 ml size of Dzing!, and the 100 ml size is slated to be discontinued at some unknown future date. You can read more at Aromascope, and thanks to Ina for permission to cross-post.
This is very discouraging news. Dzing! is weirdly brilliant and something of a cult favorite, and although we've never reviewed it, Angela has featured it twice: see Perfume Confession and The Leather Sisters.
Update: the 100 ml size of Dzing! is NOT discontinued.