While I realize that all possibilities remain, ranging from malice to complicity to incompetence on the part of the flight crew, the possible hijackers, and ATC or military staff who observed the subsequent flight of MH 370, let's see what educated guesses we can make. Let's have a thought experiment that concentrates on likely events and likely reactions (while acknowledging that other answers aren't totally discounted).
1. Is there a general feeling that a NW flight path implies piracy for future use while a SE flight path implies pilot suicide?
2. Previously, forum members were able to share maps showing the civilian radar coverage areas in SE Asia. Is the same info available on India, Bangladesh, Thailand, and Myanmar?
2a. If there are visible gaps in that radar coverage, and we assume the aircraft flew through those gaps to a destination beyond those countries, how does that flight path narrow down the remaining endurance and possible destinations?
2b. If the aircraft did not purposefully avoid radar coverage when making landfall, what reaction would we expect to a NORDO aircraft passing into India, Bangladesh, Thailand, or Myanmar? Would any professional pilots with experience flying through those countries comment specifically?
3. If the aircraft WAS landed safely at some remote site after a piracy for future use, why would that "future use" not have been carried out yet? Why wait and risk the possibility of discovery and disruption of one's plot?
4. If the aircraft was detected at the extreme southern end of this overlapping Venn diagram, 1000 miles west of Perth, are there any airfields within 1 hour of flight time that would be usable by a 777?