These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.03 s (backtrack: 0/20).

[ebuild  N     ] dev-tcltk/itcl-4.3.7::gentoo  521 KiB
[ebuild  N     ] dev-lang/tk-8.6.17:0/8.6::gentoo  USE="threads truetype (-aqua) -debug -test -xscreensaver" 4486 KiB
[ebuild  N     ] dev-tcltk/itk-4.2.3-r2::gentoo  USE="-test" 213 KiB
[ebuild  N     ] dev-tcltk/iwidgets-4.1.1-r4::gentoo  USE="-test" 704 KiB

Total: 4 packages (4 new), Size of downloads: 5923 KiB