Provide "Copy to (locale)" option in the developer console
Right now the process of adding a new language to an existing skill in the developer console is tedious, especially when the data for those languages is exactly identical.
For example, right now, the process for manually copying things on the Publishing Information tab (Launch tab on the new console) alone involves tabbing back and forth 12 different times between the two languages to copy the text from the six different fields. For an English language skill being released worldwide, that process has to be done 4 times (and that's only going to grow).
Making things worse, in the new console, each time you tab you also get forced into a "save" dialog even if you didn't change anything (as described here: https://alexa.uservoice.com/forums/906892-alexa-skills-developer-voice-and-vote/suggestions/33345916--unsaved-data-flow-doesn-t-work-properly) which further multiplies the number of manual clicks you have to make just to have a new language with identical configuration.
A "copy to (select locale)" option would be much preferrable.
Acknowledging that there are minor differences in the available intents between locales (US first name intent not available in India, etc), it would be reasonable to still do the copy but just notify the developer that their intent model needs fixing.
To expand the distribution of your skill to more locales, you can opt in to automated locale distribution. If you opt in, when you submit your skill we assess whether your skill is eligible for distribution to all locales of a given language. For example, if you support English (US), automated locale distribution can enable your skill to support additional locales like English (UK) and English (India). Please refer to the following page for more information:
Correction. This can be done in the JSON Editor.
AND...the default English is en-AU so I just added 15 utterances to en-AU and there does not seem to be a way to copy those to en-US (or en-UK).