This thread has evolved and certainly hasn't been updated frequently as far as the original subject goes. 2.3 is now in feature cut off and preparing for a beta release. 2.3 will include improvements to custom theming. I'd like to see a theming contest for a 2.x custom theme but binding a contest that never started to reworking a longly anticipated and overdue release seems silly in retrospect.
If change of course demotivates anyone to get chipping away on working on custom themes let's talk about why. I'd hate for that to happen. I think a good goal for 2.3+ is for us to destroy the conception that there is only one MODX Manager by adding more options to choose from.