The arrival estimate was amended to 0805. That's still a little odd, in that the 380 has left a little late and continues to lose time, whilst the 747 has also left late, but seemingly will gain time. The 747 cruises faster (by about 6 knots) than the 380, but you'd expect both flights to lose or gain approximately equally. So, where's the difference? Additionally, it's a rare flight that has sufficient fuel to have the journey time blow out by an hour. One potential difference lies on the ground. You can sometimes suffer delays between the gate and the runway. You've already 'departed', so that delay seems to go into the flight time. And you're on the ground, so the fuel use is minimal.
