I think a linear decrease is good but we need more early adopters to really want to back the coin. Too fast a decrease will stifle the number of people that want to get in on the ground floor.
I personally think the way to go is to decrease rewards every 7 days or 14 days - to ramp down production and still allow mining on a higher reward system for a while.
So, here is my rough plan - and this will be the final protocol change hard fork save for possible stake changes down the road which can be done via soft forks I think.
Preliminary (based on 7 day reductions):
Block 33,000: reward 2500
Block 35,500: reward 1250
Block 38,000: reward 625
Block 40,000: reward 312.50
Block 42,500: reward 156.25
Block 45,000: reward 78.125
Block 47,500: reward 39.0625
over Block 50,000: reward 20
halve the reward every 1 years afterwards
Preliminary (based on 14 day reductions):
Block 33,000: reward 2500
Block 38,000: reward 1250
Block 43,000: reward 625
Block 48,000: reward 312.50
Block 53,000: reward 156.25
Block 58,000: reward 78.125
Block 63,000: reward 39.0625
over Block 68,000: reward 20
halve the reward every 1 year afterwards
Perfect! Either 7 days or 14 is fantastic.