Dasie's are for Peace, not war.. I can see a future where people will be able to select a theme for their blog, then simple make changes to items like the background pattern or color, and the images will be able to simply adjust to the new look. Imagine drop-shadows that look good on white, gray, blue, or plaid. The only browser at this point in the way of this utopian dream is IE of Windows. The fact that IE for the Mac was the first to deliver full PNG support, 3 years ago, make the sting even sharper. [BryanBell.com]
I totally agree that from a designer POV having 32bits images support in browsers would be a major improvement in how web sites are created and managed.
Back in the "CD-Rom days" we had to use all kind of tricks to create smooth 3D looking user interfaces. Than a Director plug-in came about that allowed importing 32bit alpha channel images into our projects and at some point Macromedia realized this and made the feature default in their multimedia authoring tool. This probably happened 10 years ago!
We have already gone through all this and it's really amazing how the major browser still doesn't allow this today, especially considering that today every single GUI component in every operating system user interface is sporting one of those cool soft shadows.
If you are not a designer most probably you don't know what I'm talking about, but believe me: when Microsoft will finally start supporting this feature you will notice it.