If only Opacity Masks worked on Adjustment Layers the same way they do on clips... and if only these Masks could also be saved as Presets... we would have an incredibly easy way to create Picture in Pictures (PIPs) and vignettes!
Hopefully the new Masking features introduced in CC2014 are just the tip of the iceberg and Adobe has plans to add functionality to Masks so that they can be used by a broader range of editors rather than just the relatively few who need to blur/hide elements from a shot.
Please discuss and send your FRs to Adobe! http://www.adobe.com/go/wish