Update: 6/20 - New Super Luigi U is now available to download from the eShop
Nintendo UK has released a new trailer which highlights the differences between New Super Luigi U and New Super Mario Bros. U. The video shows how Luigi takes longer to accelerate and decelerate but can jump higher and farther than his brother, which will make for a more challenging experience. In addition, the layouts of the levels have been altered as well to give players a fresh take on the best-selling side-scroller. Also, the playable version of Nabbit is shown running through a few of the various stages - as you may know, he is meant for less-skilled gamers as he is invincible and won't take damage from enemies.
The digital version of the game will arrive as DLC on the eShop on June 20th. The standalone boxed version will be available on store shelves in Europe on July 26th, and in North America on August 25th. The physical copy is priced $10 higher than the digital edition, so that is definitely a consideration.
Video after the break.