Tone down specular highlights so my eyes do not bleed and more systems can run it.
Options to tone down graphic effects further so more players can run the game (check valve's hardware survey...)
Make the player models larger in proportion to archetecture because shooting fast moving blue (or red) dots stopped being fun in 1989.
Bring back ALL (yes ALL) of the weapons, vehicles, content, and gameplay features of the previous UT, UC, ChaosUT, and Unreal2 games.
If this insane amount of value alone does not sell the game like mad, nothing will. Consider that the mod community has tried to do this with every game iteration...
Make all of these options mutators/server configurable.
Stop using cheesy voices - hire better voice actors for taunts.
Larger player count.
Make weapons *exactly* like UT1.
In other words, make an ACTUAL upgrade, not a downgrade with prettier graphics, vastly unused engine features, and two new vehicles + fake campaign....