Technically, Notch didn't say anything about future versions not being free (he mentioned on twitter this hasn't been decided yet), the change on the terms just means that anyone that buys after the beta starts is not guaranteed to receive them for free, not that they won't.Tom Goldman said:One of the biggest points to note in this announcement is that Minecraft's sales agreement is changing. While in alpha, Persson promised the game to all players at 50% off and said that every one of Minecraft's future versions would be free to those that got in early. When Minecraft enters its beta phase, the game will rise in price from the current ?9.95 to ?14.95 (which is still 25% off the final price), and future versions will no longer be free.
EDIT: I see the article has been corrected. Good