Judging by Notch's standpoint on disc based games, it's not
No, it is a download from XBox Live Arcade.
When the update comes out.
It should be coming this summer.
It is coming out in never
It's been released in America already.
No, the XBox360 version of Minecraft is downloadable via the Marketplace.
Yes, Minecraft is being ported by a studio other than Mojang and will be on XBLA later this year.
The official release date for Minecraft on the Xbox360 is June 30, 2012
Minecraft isn't out for Xbox360 yet, but it will probably cost something similar for it on the live marketplace.
Yes microsoft payed for exclusivity of Minecraft.
The 1.8 patch was the patch after 1.7.3, which is the current stage MCX360 is in, so expect it soon.
It will be around the 20th of June->15th of july 2012 it will have all of the stuff that is on minecraft for xbox360