When Slacker first started talking about a wireless MP3 player that would learn your preferences in music and build you custom radio stations, the idea was awesome. Then more than a year passed and still no player. Meanwhile, services like Pandora and built huge fan bases offering similar services. Now the player is finally here, debuting at CES, and the idea is no less awesome. The device will come in three capacities: a $200 2-gigabyte model that will hold 15 stations; a $250, 25-station 4-gigabyte; and a $300 40-station 8-gigabyte. You can set up your stations from any browser—so the device isn’t locked to one computer—then anytime you’re near a Wi-Fi connection it will automatically load enough songs (with cover art) to keep your stations going for several hours. You can also load your own music files on it, although that will take space from the stations. And because the music isn’t streaming, quality shouldn’t be a issue. We’ll be taking the device for a test drive at the show and let you know if the reality is as great as the promise. Whether Slacker succeeds or not, I’ll be shocked if Apple doesn’t incorporate something like this into the next generation of iPhones and iPods.—Mike Haney