While the legacy Mac client continues to work (after today's patch), we are moving away from that client to the WINE client that debuted earlier this year. So, make sure to download it here if you ever run into any issues with the legacy client: http://live.ddo.com/sites/clientdl/ddo/ddolive.dmg
We don't have a firm cutoff date (yet), but people who play on Mac should consider upgrading to the newer client regardless if they can.
as i type this, the installation of the new client just crashed.