is there still a moral way to behave - when nothing you do will show in the material world in an hour or so?
Suppose the universe has an inescapable Big Crunch or Heat Death ahead - is there a moral way to behave, when nothing you do will show in the material world in a googolplex years or so?
Either way the answer is yes: all the materialist consequentialists need is a utility functional which has support at all times t rather than just at t_infinity.
This was demonstrated, in a certain limited way, in Peterson (2009). See also Lowry & Peterson (2011).
The Peterson result provides an "asymmetry argument" in favor of consequentialism:
Another argument in favor of consequentialism has to do with the causes of different types of moral judgments: see Are Deontological Moral Judgments Rationalizations?
Update: see Carl's criticism.