<Rant>
By observation, the correct procedure seems to be:

1) Get out of seat the moment the aircraft reaches the gate.
2) If in a middle or window seat, climb immediately over your neighbors.
3) Open the overhead bin containing your oversized roll-a-way (stowed across the bin taking up two spaces) - if necessary, push people's heads out of the way.
4) Pull your roll-a-way down - don't worry about the other passengers, they'll move.
5) Leave the bag in the aisle - go back and get your other bag or two which you've stowed partly under your own, and partly under your neighbor's seat.
6) Start rearranging things, calling people on your cell phone, etc.
7) When leaving the plane, stop (blocking the jetway) and place your briefcase and/or backpack onto your rollaway. Take enough time to make sure the straps are tight.
</Rant>