The arrival of this aircraft is discussed in : Official 747-8 Flight Tracking Thread #2 (by moderators Jun 23 2010 in Civil Aviation)
Start with reply 71 from Laddie,
"Company sources say that the 747-400BCF will be part of the Flight Test fleet for the next couple of months. Hmmm....perhaps to serve as a baseline against which to compare the 747-8F? But baseline for what? Noise? Fly over the microphones at Glasgow, MT, with the -400BCF, then follow immediately with the -8F?"