Can PNG be king?

I was wondering why PNG has not managed to knock-out GIF images. The PNG home page offered an excellent summary of the reasons. For those still wondering why we should be bothered about PNG, here is an executive summary: The W3C has had a recommendation to use PNG for web images since 1996. PNG has a few advantages over GIF: alpha channels, gamma correction, two-dimensional interlacing and slightly better compression. PNG is also patent free.