Dabble is one of those companies that are really innovative compared to others. The functionality to rate and discuss video material is not new, but the fact it does not matter where the material is hosted is new. Dabble offers this functionality and more :

Dabble is a media search and organization community. At Dabble, we want to make it easy for beginners and experts to organize media they care about, search, tag, describe, promote and share media.

The FAQ is quite clear about hosting :

Do you host video?

A: No, Dabble tracks more than 250 video hosting companies, and thousands of independent video websites and video bloggers, so if you have a video you want to collect or bookmark, we can get it directly from these hosters. Or, you can add a video you find on the web using our bookmarklet. By bookmarking the media you enjoy to your media page, you can keep media you care about, find it easily again, put it into playlists and share your favorites with others.

So now you can use the hosting capacity of Youtube and the other functionality from Dabble....This enables you to use other storage services too, which gives you more freedom. The only thing to worry about is which storage service to get. There are soooo many....