with some applications, like openoffice, acroread, gimp...you can copy not just text to the clipboard. E.g in acroread
with the snapshot tool, it is possible to copy a picture to the clipboard.
Very very handy feature, in openoffice/gimp  you can simply paste the graphics...

1.) when glipper is running this does NOT work anymore.

2.) a killer feature would be to extend the glipper for not just text.
E.g copy, pictures, ogg's  etc to the clipboard...

point 1 is a bug for me.

point 2:  I do not know, how the clipboard in gimp, acroread, OO for non text is implemented
..but do you think glipper could be 'expanded' for such mime types ?