Nintendo has released the new v.5.0.0 update for Wii U, which should make booting games a much less cumbersome process. The major addition to this update is a new Quick Start Menu that can be accessed through the GamePad's Power or Home button.
The Quick Start Menu will allow users to access recently-played or newly-installed games, significantly reducing the game's start time.
Other items included in the v.5.0.0 update include the ability to download system updates automatically while the Wii U is in Standby mode. GamePad Alerts can also be displayed on the GamePad screen while the Wii U is powered down, though this option can be disabled through the Power Settings menu.
The full list of changes can be found here. To update the Wii U manually, select Settings and System Update near the bottom of the screen.
Credit to Chatty's NastyJack for the tip.