Snopes.com shot down this rumor years ago (apparently, it's at least six years old).
http://www.snopes.com/politics/business/cell411.asp
(Edited to place emphasis on the fact that this is nothing more than a rumor, a long-lived one at that. Please, if anyone claims that this is true, direct them to the website listed. Granted, that's not to say putting your landline or cell number on the No-Call list isn't a good idea - it is, since telemarketers do NOT distinguish between a land line and cell number, especially if they use a random dialer. So yeah, there's no ultimatum saying that you must register your number before a certain date to avoid unwanted calls, nor are they being "released" to telemarketers.
Furthermore, if you want to avoid being charged for unwanted calls if you don't have an unlimited plan, don't pick up any phone calls that show up as unknown or restricted on your Caller ID, and don't pick up for any number you don't recognize. Let your Voice Mail pick it up. If they have anything worth saying to you, they will leave a message and you can call them back later.)
Last edited by Lyriel on 26 Jun 2010, 5:58 pm, edited 1 time in total.