I should have said Bom isn't currently part of the discussion.. not that they won't be part of it, I have no idea.. but right now a manufacturing partner has not been identified..
If you want my take on the possible expansion, look for it in the thread from a couple of months ago... Like I said there.. A study was launched mid last year with regards to a large scale monorail expansion at WDW.. While busses are cheaper, they are not nearly as effective at moving massive amounts of people at once.. Look at the staton 18 backups that happen when monorails are down at park closing (or post MSEP/Wishes).. you've got a 1 1/2 to 2 hour wait for a bus ahead of you.. Not to mention the safety implications of having that massive of a crowd stagnant by the MK bus terminal.. It's not pretty, and not good, and they are working on it.