On alpha worlds, block changes only take place on newly generated chunks.
The beta version of Minecraft was released on December 20, 2010.* * Minecraft-beta came after Minecraft-alpha, but before Minecraft 1.0. You can play Minecraft-beta with the new launcher.
Yes, it has been updated from beta that you can create as many worlds as your hard drive can hold (for an average hard drive, that's allot of worlds!)
no you need minecraft beta to play beta servers
As many as you want, as long as you have enough computer space to create the folder in OS (C:)/Users/(your computer username)/Appdata/.minecraft/saves.
The regular download as of Minecraft 1.8 is the Beta Minecraft. The last Minecraft update I believe will be the "Final" product and official game and no longer be a game in Beta.
When the full Minecraft game is released you will have it if you buy the beta.
Minecraft is currently scheduled to leave beta November 18th of 2011
Beta 1.0
Yes. And Minecraft Beta 1.8 with crafting, furnaces, chests and stuff is called "Minecraft Beta" or "Survival Mode".
Alpha was an earlier version on minecraft beta, it has poorer graphics, less blocks and far fewer crafting recipes.
No
i dont think youcan buy minecraft beta but minecraft 1.3.2 /1.0 cost $26.95