According to tvshowsondvd.com it looks like Warner Home Video is "strongly considering" a Silverhawks dvd release in the not so distant future. In their 2007 Online Chat with Home Theater Forum they discussed the possibility of this release along with a number of other projects on their slate for '08. And tvshowsondvd has learned from their sources that a Mid to Late '08 is being eyed as a possible timeframe.
This may still be just a rumor, but at least its from a reliable source.
I think we can all agree this is really awesome news