The aircraft type for this route is all over the map.
started off with A340 when I booked an award seat a number of months ago for a trip in March 2011. When I tried to confirm the seat assignment and called them beginning of Jan 2011, they said that they couldn't assign me the seat yet as the aircraft type is not certain at the time. Told me to call back. I thought that maybe they will put the new 777 on this route by the time I'm travelling.
Checked yesterday and it showed the 77W with first class, so I called in to get upgraded from biz to 1st.
The likelihood that they are swapping the aircraft again between now and end of March is still pretty high, so... who knows.