The Democrats avoided that problem, but too much proportionality combined with too much front-weighting meant that that when the Rev. Wright videos finally emerged on March 13, 42 states had already had their say. And the proportionality of the delegate distribution in the last eight states meant that Hillary's task was close to hopeless, making the eight states after March 5 anti-climactic.
So, you can see the problems: too much frontweighting and either too much winner-take-all or too much proportionality.
The states have been trying to get their primaries up early so that they get some kind of a say, and the states generally prefer winner-take-all to magnify their importance. The obvious solution is to make the two desires work against each other:
Set a rule that the first state primary or caucus in 2012 has to be 100% proportional and the last state 100% winner-take-all, with a sliding scale in-between. This would give states an incentive to hold back in the calendar so they can be more winner-take-all. Meanwhile, it would prevent premature climaxes like the GOP in 2008 and long-drawn out anti-climaxes like the Democrats in 2008.