Welp, Donald's already out.
We have a date and opportunities to attend Nintendo Live, but it's largely US only.
The live show will run from September 1 - 4 (Labor Day long weekend) at the Seattle Convention Center, the same weekend as the PAX show in Seattle. PAX attendees can request tickets separately, or registration will be open from May 31 - June 22 on the event website.
Aside from PAX entrants - who can enter on the show's website from May 31 - July 7 - registering requires a US-based Nintendo account, and multiple registrations require the accounts to be linked to the same family group. There are no game announcements planned.