First, the Music account, twitter.com/iTunesMusic , will provide information on "new releases, pre-orders, iTunes LP, exclusive offers and more."
Second, the Podcasting account, twitter.com/iTunesPodcasts , will provide a "Podcast Episode of the Day, from iTunes Podcasting."
Next, the iTunes Movies account, twitter.com/iTunesMovies , doesn't contain a description, but does contain one tweet so far, and it looks like it will be used for Movies on the iTunes Store.
Finally, the iTunes TV account, twitter.com/iTunesTV , which contains no tweets yet, will provide "Official TV updates from the U.S. iTunes Store on Twitter."
Will these accounts make a impact on what you discover in the iTunes Store? Let us know in the comments below!