Because the 2.6.x introduces a new set of features, backporting it to hardy is not trivial. This bug applies only to Jaunty and Intrepid, for which GIMP is already in version 2.6.x. For these 2.6.4 is a bug release.
If you feel 2.6.x should be backported to hardy, you should file a separate bug.
There are third parties repositories that offer GIMP 2.6 for hardy. Being totally unofficial, you should however be careful in using them.
Because the 2.6.x introduces a new set of features, backporting it to hardy is not trivial. This bug applies only to Jaunty and Intrepid, for which GIMP is already in version 2.6.x. For these 2.6.4 is a bug release.
If you feel 2.6.x should be backported to hardy, you should file a separate bug.
There are third parties repositories that offer GIMP 2.6 for hardy. Being totally unofficial, you should however be careful in using them.