In these hours the version has been diffused on Internet pre-release (that is does not complete) of patch the 1.8. In order to use it continuations these instructions:
1. DOWNLOAD Minecraft 1.8 Offline Installer: Unloaded the rows minecraft.jar from this address:
http://assets.minecraft.net/1_8-pre/minecraft.jar if it did not have to work you can unload same the rows also from here: http://www.gamefront.com/files/20761300/minecraft.jar
2. Replaced the rows as soon as unloaded (minecraft.jar) with that one with the same present name in your folder of Minecraft. (IMPORTANT: fairies before a copy of backup of your rows).
On Windows XP it is in: “C:\Documents and Settings\Admin\Dati applications \ .minecraft \ bin” If not sapete where a search in C is found these rows in your OS fairies: for “minecraft.jar”.
3. You start Minecraft normally. The innovationes remembered to create a new world otherwise will not be able to see all.