Originally, Ballmer wanted the Metro-Style/Windows Store version to launch first; however, he may have had a change of heart.
According to one of my contacts, Ballmer OK'd the suggestion by the Office team that they'd bring Office for iPad to market as soon as it was ready, even though that would likely mean before the Windows 8 version. I'm hearing that new date for Office for iPad is some time in the first half of calendar 2014. (My sources last summer were hearing Office for iPad wouldn't debut until Fall 2014.)
It's unclear how Microsoft will make Office for iPad available. However, Foley says it probably will require an Office 365 subscription and it may save files by default to OneDrive (the soon-to-be-renamed SkyDrive).
Microsoft has already made Office Mobile available for iPhones and Android phones, with an Office 365 subscription.