Not only that, but the same app is also available for Windows Phone as a dedicated piece of software now with its own listing in the Marketplace. Granted, you were using it before with your WP device for storing photos or docs, but the dedicated app allows you extended functionality now.
You can view previously uploaded Office docs or PDFs within the app, and send links to any other existing file type you've stored for sharing, with an exclusive permission to edit (in the online version of Office for docs), or as read-only.
The cool thing about SkyDrive is that you can also stream your music files from it, so essentially Microsoft is giving iOS users a 25GB cloud music storage service for free as well, in addition to sharing Office docs and other file types. You can only upload photos and videos from the phones, though, the other files are for strictly for sharing and download, but SkyDrive is having new features added quite often these days.