Instructions on how to modify the Minecraft.app for OS X to work with Java 7 (without the need for 6). See the instructions in the "ReadMe" section.

ReadMe - Instructions.txt

These instructions are for Mac OS X 10.7.3 and later (those that can run Oracle's Java 7).

This assumes you have the Java 7 JDK installed from: http://www.oracle.com/technetwork/java/javase/downloads/index.html

When you download and install Minecraft.app into /Applications, you can control-click or right-click on the Minecraft.app file and "Show Package Contents".

Inside the "Contents" folder inside, there is a "Info.plist" file, which is plain text. Open this "Info.plist" file in a text editor of your choice and replace the contents with the "Info.plist" listed below.

Then open the Terminal and run the following commands:
touch /Applications/Minecraft.app/Contents/MacOS/LaunchGame.txt

This will create a blank text file called "LaunchGame" inside the Minecraft.app/Contents/MacOS folder.

Open the file and paste in the contents of the "LaunchGame" listed below.

Then run these commands in the Terminal:
mv /Applications/Minecraft.app/Contents/MacOS/LaunchGame.txt /Applications/Minecraft.app/Contents/MacOS/LaunchGame
chmod +x /Applications/Minecraft.app/Contents/MacOS/LaunchGame

As a last step - you should be able to double-click Minecraft.app and now it will launch using Java 7 (assuming it's installed). If you get an error message about an unknown developer, you may either have to adjust your Gatekeeper security settings in OS X or (easier) if you're an admin, you can just control-click / right-click on Minecraft.app and select "Open" and it will let you open the file successfully. Once you've done this once, double-click should work from that point on.

Info.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist SYSTEM "file://localhost/System/Library/DTDs/PropertyList.dtd">
<plist version="1.0">
  <dict>
    <key>CFBundleDevelopmentRegion</key> <string>en</string>
    <key>CFBundleName</key> <string>MinecraftLauncher</string>
    <key>CFBundleVersion</key> <string>1.0.1</string>
    <key>CFBundleShortVersionString</key> <string>MinecraftLauncher 1.0.1</string>
    <key>CFBundleExecutable</key> <string>LaunchGame</string>
    <key>CFBundlePackageType</key> <string>APPL</string>
    <key>CFBundleSignature</key> <string>????</string>
    <key>CFBundleGetInfoString</key> <string>MinecraftLauncher 1.0.1 © Mojang Specifications, Inc, 2013</string>
    <key>CFBundleIconFile</key> <string>favicon.icns</string>
    <key>CFBundleAllowMixedLocalizations</key> <true/>
    <key>CFBundleInfoDictionaryVersion</key> <string>6.0</string>
    <key>CFBundleIdentifier</key> <string>com.Mojang Specifications.Minecraft.Minecraft</string>
    <key>LSHasLocalizedDisplayName</key> <true/>
    <key>CFBundleDisplayName</key> <string>Minecraft</string>
    <key>NSHighResolutionCapable</key> <true/>
  </dict>
</plist>

LaunchGame

#!/bin/bash
SCRIPTPATH=$(cd $(dirname $0);pwd -P)
/usr/bin/java -Xdock:icon="$SCRIPTPATH/../Resources/favicon.icns" -Xmx128m -jar "$SCRIPTPATH/../Resources/Java/Bootstrap.jar"

I'm using an early 2007 MacBook I've tried using this method on other apps and it bounces the app up once and then quits unexpectedly I think I know why correct me if im wrong but its a 64 bit app im trying to run and its a 86x64 system