Verified via this- 1) emerge -C sed 2) USE="nls" emerge sed 3) Go insane as gettext gets pulled in and tries to use sed. The modifications that the gettext ebuilds do via sed should be made into patches, to eliminate the sed dependency. Either that or remove the nls use flag.
Sed (as well as other base tools) is already in stage1, thus this is not needed. If you consiously unmerge sed or another important tool, then you should know you will run into issues.
