Should he resign? Not just because of this last scandal, but because of all his past mistakes, miscalculations, lies, deceptions, incompetence, and whatever else anyone thinks of.
If he is the top responsable for the US military (not counting the president), shouldn´t he take his fair share of the blame, just like any general or any other officer in charge of the operations?
Presidents have fallen from grace for much less.
But although Bush claims to be angry at him for not having been kept in the loop on the full scope of the abuse issue, it doesn´t seem he´s willing to cut Rummsfeld off, even though it would help minimize some of the huge ammount of pressure.
But if we analize Rummsfeld´s performance, it has been quite below average, sub-par even!
Let´s check out a few of the charges against him:

-He totally miscalculated the costs of the war;
-He misplanned the war, thinking it would take less troops than what actually was needed;
-His post-war planning was non-existent;
-He lied, deceived, misled, or tricked the troops regarding extended tours of duty overseas;
-He allowed situations of appalling abuse on detainees to take place on facilities under his direct jurisdiction;
-He commited troops to the aftermath of the main conflict, that were totally unprepared and untrained to conduct peace-keeping and order-keeping operations;
-He failed to produce any valid evidences to support the subsequent invasion and oiccupation of a sovereign nation;
-He "embezled" funds destined to Afghanistan, and used it in Iraq;
-He failed to conduct a "clean" war, with the US troops oftenlly commiting acts of brutality and targeting civilians, leading to frequent massacres and unnecessary bloodshed amongst the civilian population;
-He failed to rebuild the infrastructures destroyed in the course of the war;
-He failed to supply the US troops with all the necessary means for conducting their field operations (often the troops had to buy their own body armour, and use weapons captured to the enemy);
-He failed to capture and eliminate key taliban and Al-qaeda principles, although he had almost 2 years, almost unlimited funds, and many thousands of troops on the ground to do so, allowing the Taliban to resurface again in the south;
-He conducted media espectacules during certain operations, with the intent of glorifying the US troops, and vilifying the iraqis, namelly the Private Ryan rescue, and Saddam´s capture;
-He totally allowed the international Rules and Laws of War and the Genevre Convention guidelines to be sistematically infringed and violated on the field;
-And finally, he his totally guilty of having a below 80 IQ, a speech impediment, and a poor speech writer, just like his mentor Bush.
Oh yeah, he is also guilty of comming up with the most ludichrist and outlandish comparisons and cockeyed explanations i have ever heard!

Why in hell would anyone want such an incompetent baffoon on his cabinet, is beyond me!

PS: Tried to make a poll for this, but i never did one before, so i don´t know how.

__________________
"Quincitilius Varus, give me back my legions!"
Emperor Augustus of Rome.