The 744 will continue for a few more years yet but it is undoubtedly nearing the twilight of its production life. Boeing has virtually conceded that further substantial development of the aircraft is unlikely and a combination of the A380 above and the 777/A340 below must naturally mean its market will decline.
A further problem now confronting the 747 is that with Boeing stopping further major development it is unlikely it will ever achieve Chapter 4 noise standards. This will mean that it will continue to be affected by curfew restrictions at airports such as LHR, SYD etc. The A380 must achieve Chapter 4 (contractual requirement of SQ and QF) so it will not be curfew restricted. This difference will be a key attraction for airlines going forward.