Reuters has a good summary article on the current levels of insecurity in Sudan entitled, Attacks on aid groups cripple Darfur relief.
Darfur is an interesting case study from a high-level, security management standpoint. I know of at least one large NGO that was advised to suspend operations in Darfur due to insecurity, but continues its programs mostly because senior management believes the public relations benefits outweigh the staff exposure to risk.
In my opinion, most humanitarian organizations don't do a very good job of clearly establishing and articulating acceptable levels of risk to staff. It would be useful for senior management to brush up on some basic economic theory in cost/benefit ratios, especially as it applies to staff members.
What are we willing to risk to achieve our mission? Is the death or rape of a staff member simply the cost of doing business? Is one death OK, but will two cause us to suspend operations? Is the humanitarian work we are performing really making a difference compared to the level of personal risk staff is experiencing? Very hard questions, that are all too infrequently asked.