The GIF patent expires today. Some people feel this will be the end of the PNG format, but PNG is still superior to the GIF format. So perhaps, technology will get the better of economics. But until IE supports the PNG, it may be a lost cause
[Brad Choate: 4,558,302]
[Brad Choate: 4,558,302]

Gif still has its place, but png is far better.
What is needed is a thing like jpg, but with animation and transparency.