Bjoern,
Not to be hardheaded or attack you but why should it make sense to you?
I need the ability to save images to other formats then is available and why does not concern PCS prof. I can explain why I need it, but why should they care in mine opinion it is not why developers want it but how many will convince them.
However I do agree with which file formats. But at least TIF, multi-page TIFF, ICO and animated GIF. I also like PSD, PDF/A and much more...
All with support for 1-bit, 4-bits, 8-bits, 16-bits, 24-bits, 32-bits, 48-bits, 64-bits and 128-bits image color depth.