That's right, but if you click on "Open" you will be prompted with a dialog that let you chose one of "Run in Terminal", "Display", "Cancel" or "Run". If you chose Display the file will be open with the default Text Editor.
If you actually want to add that option again, just select Properties, go to the Open With tab and make a default application different from Text Editor (for example OpenOffice, see screenshot 1). In this way when you right-click the entry "Open with Text Editor" will appear (see screenshot 2) since it is not the default application anymore. But if you click on "Open" and then "Display" the file will be feed into OpenOffice.