Don’t shoot the messenger, but here is what I heard (I don’t care whether or not anyone believes me, but I have a pretty good track record when it comes to this type of stuff and my sources are usually pretty in-the-know). As many may be aware, the seatmaps on united.com don’t accurately represent whether a flight will be served by a newly configured aircraft or not. Many people on UA916/917 between IAD and FRA in April think they’ll be flying the newly configured 747, but apparently United changed their plans. Now the newly configured 747 will debut on ORD-SFO-ORD in April, something United is doing to work out all the glitches in the system before it goes onto an “important” international route, a smart move in my opinion. Also, the newly configured 767’s that are currently operating IAD-ZRH and IAD-FRA will switch to ORD-LHR around the same time.
I wouldn’t change my plans based on that info, but I certainly would take it into account when making your travel plans.;) Of course this is also assuming that there isn’t a delay in the process, which judging by the 767 there’s always a chance of.