It was but a couple months ago that Yahoo gave its mail service a sprucing, adding some new features while subtracting others. Tabbed viewing was among those pruned, thanks to user feedback that tabs became difficult to deal with in great numbers. Well, tabs are back, with a brand new (for Yahoo) invention: a 'Preview All' feature that lets you see all your tabs at once in tiled fashion. You can also assign the feature to your ESC key to make switching between regular and tiled views a quick and painless affair. Got it? Good. The new functions will be rolling out to users everywhere in the next few days.