Metro Mail handles multiple accounts separately
In Windows Consumer Preview, multiple email accounts caused enormous headaches. In Release Preview, there are three columns, and they stay put. The first column has one entry for each of your email accounts: Click on an entry, and the Inbox, Drafts, Sent Items, and so on appear for that account only. (Click to enlarge.)
The iPad’s Mail app lets you choose which account to view, or it lets you consolidate all of your accounts, so you can read all of your messages at once. Just sayin'.