As of patch 3.3.3, some people have noticed that some of their level 70 gear is now missing gems and enchants -- they've simply up and disappeared. It only appears to be affecting gear and equipment acquired prior to Wrath, so level 80's shouldn't have too much to worry about -- but for leveling alts, or mains that are taking their time, it's definitely a concern. This has been reported, and there is a blue response on the issue:
So for now, if you've noticed your gear has significantly less sparkle than it did prior to Tuesday, sit tight and don't do anything to it -- it should be fixed next Tuesday with the regular weekly maintenance. If there's any changes to this information, we'll let you know.