The "typical" thing is just absurd, but I do find the Wright issue a little disturbing. I am conservative, so I don't like either candidate. Maybe that allows me to be a little more objective.
Obama's main arguments in his speech are that a) he wasn't aware of the extent of his pastor's beliefs cause he wasn't there when Wright said them, b) Wright is a justifiable product of a different era, c) he can't disown Wright just like he can't disown his grandmother, and d) he often didn't agree with Wright anyway.
On point a, Obama has previously claimed he is a devout Christian. Well a devout Christian goes to church and would understand all his pastor's beliefs. Something doesn't add up. I personally think most politicians in either party are lying hypocrites, so Obama probably, like most politicians, uses church to drum up votes. In this scenario, it is quite reasonable to believe that Obama wasn't fully aware of his religious mentor's beliefs.
On point b, there is some truth to this. But it contradicts Obama's statements that what Wright said is completely unjustifiable. However, I think this is a non-issue.
On point c, what the hell? This is offensive to me. He basically tosses his grandma under the bus for political gain. Yes, grandma's views are bigoted. But choosing as a conscious adult to be mentored by a blatant racist and being raised by a woman who loves you who has a mild form of bigotry are completely different things. The key point here is that you choose your pastor, you don't choose your family. Moreover, Wright's bigotry is exponential more racist than grandma's. Moreover, I think politicians (again many do this in both parties) who use their family for political gain are slimeballs. I would never insult my family, true or not, if I was in trouble in my job.
On point d, then why was he Obama's religious mentor?
I think the truth of all this is that every politician in America needs a few things to get elected: Christian credibility, moral high ground, and celebrity/charisma. Obama was always going to have an uphill battle with questions about Islam (sad that this is the case) arising during his political career. What better way to quiet those questions than to convert and join a large church that also helps him with a powerful voting block in the democratic party? Obama probably really wasn't all that aware of the views of that pastor, it was just a convenient tool among many others in getting elected.