Yahoo is not the only mail provider using an HTML5 interface optimized specifically for the iPad. Google has been doing it for a while now, and they just recently announced a new ‘Stacked Cards’ interface tweak that hopes to make management of multiple conversations less confusing while allowing the code monkeys to experiment with CSS3 transitions.
According to Google, a constant source of confusion for many users were two different but similar looking toolbars in the Gmail interface. A toolbar on the top right performed actions on the currently open conversation, while a toolbar on the bottom left performed actions on any selected conversations.
The new interface has just one toolbar, and it performs actions on the current conversation. If you have multiple conversations selected, they appear as stacked cards and the toolbar options will apply to the entire stack. Not only does it sound simpler, it also sounds more logical.
To play with the new features simply open up Gmail in Mobile Safari on the iPad. Sorry world, the feature is currently limited to those inside the US.