This BBC piece looks at the pressures on Afghanistan's President Hamid Karzai as he wiggled Abdul Rahman off the hook of an apostasy charge by having the Muslim-turned-Christian declared mentally incompetent.
It's a decent general overview of the case at this point.
The fun fact: No one has ever been executed in Afghanistan for apostasy, even under the Taliban.
Here's a journo-centric bit of info:
In similar cases in recent years, two Afghan editors accused of blasphemy both faced the death sentence, but one claimed asylum abroad and the other was freed after a short spell in jail.
And here's a related story: Italy mulls Afghan convert asylum
What the hell, one more: What Islam says on religious freedom