I vote for 401k's and SS for everyone with no other pension system. Folks should work where they want based on current compensation and their own current career preferences and not because they already have many years invested in "the pension."
It would be nice if the Government opened up the TSP to everyone. I can't imagine the cost would be that high. As it stands now, many employees are paying such high fees that it is barely worth the tax break. Others have no access to a 401k/457 type plan.