The world's four biggest music corporations-- Universal, Warner, EMI, and Sony BMG (soon to be Sony Music Entertainment Inc.)-- have teamed with MP3 player and memory card manufacturer SanDisk to create a new music media format called slotMusic.Here's how slotMusic works: These memory cards-- which come pre-loaded with albums in DRM-free MP3 format along with liner notes, album art, videos, and other content-- plug right into phones, portable media devices, computers, and even a few car stereos (with aims at more). Each card sells for about the price of a CD and also comes with a USB adapter to ensure the easy transfer of content from the card to a computer or portable MP3 player.The initial run of slotMusic cards is now shipping and includes entries from Coldplay, Weezer, M.I.A., Young Jeezy, Usher, Rihanna, Ne-Yo, Katy Perry, ABBA, Jimi Hendrix, Elvis Presley, Lynyrd Skynyrd, and Keane, among others.But here's the rub: Other than the fact that they're playable on cell phones, these cards don't seem all that different from CDs. They're smaller, but they still come with one album per physical artifact, implying you'd need some sort of carrying case if you wanted to switch between Kala, Skynyrd's Greatest Hits, and One of the Boys (just me?) on the train ride to work. A smaller physical format with limited capacity is still a physical format with limited capacity! Not to mention the fact that plenty of cell phones already come with the capabilities to download music.Maybe the glaring holes in this plan to revolutionize the way people consume music are why the slotMusic press release ends with a blatant admission that it "contains certain forward-looking statements" that "involve numerous risks and uncertainties." Risks and uncertainties such as this one: "Market demand for our products may grow more slowly than our expectations, or there may be a slower adoption rate for these products in new markets that we are targeting."slotMusic: This is gonna change everything. Or nothing.