Oh goody, more partisan political backslapping, how nice
I don't think Obama had any choice, but with the extremists on the right, it's a "damned if you do or damned if you don't" kind of thing
anyway.
Since Obama originally defended his pastor, the guy went out and said a bunch of even crazier stuff on national TV.
I sympathized with him actually, for a lot of religious people (and I think Obama is one) your pastor is like a member of the family.
We've all had a crazy member of the family or two, I wouldn't want to have to publicly 'disown' any of mine.
And as usual, he explained his decision
pretty clearly (and as usual, certain people with a clear
ideological agenda will ignore that):

"I'm not denouncing the church and I'm not interested in people who want me to denounce the church," he said, adding that the new pastor at
Trinity and "the church have been suffering from the attention my campaign has focused on them."
Obama said he and his wife have been discussing the issue since Wright's appearance at the National Press Club in Washington last month that
reignited furor over remarks he had made in various sermons at the church.
"I suspect we'll find another church home for our family," Obama said.
"It's clear that now that I'm a candidate for president, every time something is said in the church by anyone associated with Trinity, inlcuding
guest pastors, the remarks will imputed to me even if they totally conflict with my longheld views, statements and principles," he said.