Just reading on the V-Flyer forum that some of the A330 aircraft that VA were having have now been leased to other airlines and VA are only getting 2 of them, so don't know how many will end up on the MCO routes this year
If you want to know what aircraft Virgin plan to use on any particular flight, then make a dummy enquiry and if you click on the flight number (which is in red) then a new box opens and it tells you which aircraft it is.