1-Up Studio is known for many games but one famous game they created is Mother 3. With the games critical reception worldwide (despite lack of an official localization), they are a studio with much respect pushed towards them. Nintendo is inviting them for the Switch Event, which likely means little; they are a studio of Nintendo, so they should know what is going on with the Switch announcement, pricing and what not.
But this could indicate that rumors surrounding an official Mother 3 localization might have some truth to them, as they are attending the event and could be developing the game, considering they were the original developers for the GBA version. Thank you Nibel (@Nibellion) for reporting this originally on Twitter!