Hummingbird contains a great option to deliver images via the WPMUdev CDN which is transparent and good on multisite.
Jetpack has this but also has full video hosting, integrated with the media library – where uploading a video through the library is redirected via wordpress.com's own hosting, transcoding and delivery, so no videos are stored on your local server. The drawback is it has to be manually activated on each site in a network.
Hummingbird would be AMAZING if it could offload the hosting of ALL uploads to the library, transparently and automatically across a multisite. Would then make web servers much easier to load balance.
Though Jetpack's unlimited hosting is included in their membership, a full media offloading I think is more valuable and could be charged on a per-TB basis. We'd pay for sure!