Windows 8's new Metro environment doesn't include a file explorer app, but it does include a SkyDrive file explorer app, just one of several hints in the new OS that Microsoft's cloud storage solution will take on a much more important role going forward.
Microsoft SkyDrive is an online cloud storage, aimed at consumers, that provides 25 GB of free storage space and will soon offer paid tiers of storage as well. To date, accessing that storage hasn't been particularly easy or seamless: Microsoft doesn't build native SkyDrive support into Explorer, for example, and enthusiasts who are interested in getting the most out of the service have had to resort to third party utilities such as SDExplorer and Gladinet Cloud.
In Windows 8, this is all changing. With this wave of technology, Microsoft is building SkyDrive support right into the operating system, letting consumers sync key settings between PCs through the service, utilize SkyDrive storage via the new system-level file picker, and via a native, Metro-style SkyDrive app.
(Microsoft will also be releasing a SkyDrive application for the Windows desktop; this will run on Windows 7, Vista, and 8, and be available later in the year. I will write about this application separately when it appears.)
The SkyDrive app is interesting on a number of levels. For example, while such an app would obviously require an associated Microsoft account (or what we now think of as a Windows Live ID), SkyDrive is unique in Windows 8, I believe, in requiring that you sign into the OS using a Microsoft account. With other online services-connected apps, like Mail, People, Calendar, and Messaging, you can sign in normally with a local account and then just sign into Windows Live the first time you use one of those apps. But SkyDrive requires that OS/Microsoft account sign-in integration for some reason.
Once its up and running, the SkyDrive app is obvious enough. It features a standard, full-screen, Metro-style UI that replicates the layout of your SkyDrive storage in Microsoft's latest design language. To see how the same content can look so different, consider the following screenshots, which show you the top-level SkyDrive view of the same account in both Metro (top) and web (bottom) views.
In this Metrofied vision of cloud storage, folders are rectangular tiles, and those that contain photos contain previews. Documents, too, are tiles, this time in square form, with a document title appended to the bottom.
Navigation is pure Metro as well, of course, and increasingly familiar as my experience with this system grows on various device types. There's a prominent Back button in the top left corner of each screen, a title-based menu that reveals often-used locations such as the root of your SkyDrive storage, recent documents, and shared documents, and a very simple app bar with Refresh and Add buttons. (The latter for uploading files, curiously. New folders, as you ask? Don't.)
To open a document, you simply click (or tap) it. The resulting action will depend somewhat on your file associations. Text documents open in Notepad, by default, for example, and PDF files open in Windows Reader. But Office documents, surprisingly, open in the corresponding Office Web App, in IE 10 Metro, and not in an actual Office application on your PC.
Microsoft currently supports some basic photo sharing functionality in SkyDrive, but none of that is present in the Metro app. Folders full of photos are decent looking, with tiled thumbnails, and you can view photos full screen, of course. But you can't start a slideshow or institute any sort of sharing from the folder view. (Sharing only occurs singly, at the file level.)
To upload files to SkyDrive, you use the aforementioned Add button in the app bar. This brings up the standard Metro-style file picker, which lets you collect files from different locations the PC file system and other locations in its "basket" and then upload them all at once. I don't see a way to add folders.
To download a files from SkyDrive to the PC, select it and then display the app bar. Then, select the Save Local button. You can only perform this action on individual files, not on multiple files or folders, unfortunately. (And not on all file types: You can't download web-based OneNote notebooks, for example.)
SkyDrive of course supports standard, system-level features like Share and Print (via the Share and Devices charms, respectively) as well, but only at the file level. Printing in particular seems to confuse people for some reason, but I suspect it's one of those things that will come more naturally with experience.
Like the other App Previews in the Windows 8 Consumer Preview, the SkyDrive app is woefully incomplete in this current version. There's a ton of missing functionality, though the navigation basics seem to be in place. Hopefully, we'll see a more fleshed-out version of this suddenly very useful app soon.