SkyDrive is what ties together all of Microsoft's Windows Live online apps. SkyDrive is what allows integration between services as well as Dropbox-like syncing between various devices. The new version coming to Windows 8, and presumably the Windows Phone and iOS apps as well, will be adding a number of features to allow for better creation, managing, and sharing of files.
Currently, the service offers 25GB of free storage, but the new version 16.3 will be adding paid options to increase your storage limit. It will also increase the individual file size limits to 300MB, although there is no word on if that limit will be even higher for paid users. Microsoft is also adding new apps for Mac and PC to allow management of online files and access to local files from the web.
Interestingly, Microsoft is adding support for the creation of OpenDocument formats with the new version as well. Until now, users could only create files using Office file types. Sharing is also getting a boost with the addition of easy sharing to Twitter as well as a URL shortening service, although there is no word on if the service will have as many options as something like Bit.ly.
That's a pretty nice round-up of features, and it should help Microsoft to fare well against Dropbox, iCloud and Google Drive. Now, we just need to see the mobile app updates that will add these new features.