Because no-one uses Yahoo Mail anymore?

(On a more serious note I think this is a 'copy' of an iPhone app for gmail (?))
Not sure how hard/possible it would be to incorporate different email providers into one interface like this (menu options would have to be dynamic as different email providers have different features (archive and tag for gmail for instance).
Sounds like a pain and personally I'd much rather have one app like this that does gmail very well - as opposed to an app that does a generic way of handling multiple email systems.
I guess there's always modest mail (ugh).