Lucas will be available in June, no other information has been released.
If you registered both Super Smash Bros. for Wii U and Super Smash Bros. for 3DS with Club Nintendo before March 31st, you will receive the download code to play as Mewtwo via email on April 15th. If you didn’t, he will be available for purchase on April 28th for $3.99.
The Nintendo Direct on 1/14/15 official announced the New 3DS and New 3DS XL are coming to the United States and United Kingdom on February 13th. The United Kingdom will be receiving both the New 3DS and New 3DS XL, as well as faceplates that are only compatible with the New 3DS. The United States is only getting the New 3DS XL, which is not compatible with faceplates and does not come with an AC adapter.