alloy.py

import sublime, sublime_plugin
from os.path import splitext
from os.path import isfile

class MoveWindowCommand(sublime_plugin.EventListener):
    def on_load(self, view):
        window = sublime.active_window()
        myView = window.active_view()
        fileName, fileExtension = splitext(view.file_name())
        if fileExtension == '.xml':
            window.set_view_index(myView, 1, 0)
        elif fileExtension == '.tss':
            window.set_view_index(myView, 2, 0)
        elif fileExtension == '.js':
            window.set_view_index(myView, 0, 0)
            if isfile(fileName.replace('/controllers/','/views/')+'.xml'):
                window.open_file(fileName.replace('/controllers/','/views/')+'.xml')
            if isfile(fileName.replace('/controllers/','/styles/')+'.tss'):
                sublime.set_timeout(
                    lambda: 
                		window.open_file(fileName.replace('/controllers/','/styles/')+'.tss')
                	, 100)
        else :
            window.set_view_index(myView, 0, 0)

Main.sublime-menu

// Put me in: ~/Library/Application Support/Sublime Text 2/Packages/User/Main.sublime-menu

[{
    "id": "view",
    "children": [{
        "id": "layout",
        "children": [{
            "command": "set_layout",
            "caption": "Custom: 3 Pane",
            "mnemonic": "C",
            "args": {
                "cols": [0.0, 0.5, 1.0],
                "rows": [0.0, 0.5, 1.0],
                "cells": [
                    [0, 0, 1, 2],
                    [1, 0, 2, 1],
                    [1, 1, 2, 2]
                ]
            }
        }]
    }]
}]

Any reason why this doesn't work when there is no previous file open?