Actually, the answer to the OPs question appears to be yes.
You can end your turn in mid-jump. The rules state that this can happen, so it is merely a matter of contriving your movement so that it happens.
The further question of whether you can attack and get a bonus to hit because of that is more problematic, but still doable.
For example, you could get an AoO while "hanging in mid air". An AoO is not an action, so it can be done.
There is probably at least one feat or PrC special ability that allows you to do a normal attack outside of your turn and outside the Ready action, but that would not be a move action, so it could not be used.
And, of course, an Elocater can do this (jump, float, attack or ready an attack).
Hyp's Ready "trick", although clever, could not be used because the next action is not a move action: "your next action (either on this turn or, if necessary, on your next turn) must be a move action". Next Action here cannot refer to next turn due to the "either on this turn ..." phrase.