For one of America's youngest presidents, in office less than nine months — and only for 12 days before the Nobel nomination deadline last February — it was an enormous honor.
The prize seems to be more for Obama's promise than for his performance.

The Egyptians reactions started with announcements on Twitter

Then some others were really astonished.

While the majority started making fun of it

Arabawy also wrote a special post about it in his blog.

The butcher of Iraq and Afghanistan (and Pakistan) has won the Nobel Peace prize. Congratulations! [Mabrouk!] It’s a great day for world freedom. Obama, Manachem Begin, Henri Kissinger–all men who made this planet a great place to live in. Why can’t Mubarak and Habib el-Adly get it too? The message those a**holes in Norway are sending: Murder and butcher your way to Nobel.

And finally, some others had a different point of view:

K, a recently returned Marine Embedded Tactical Trainer (he worked with the Afghan National Army), noted that the attack itself didn't have to happen.

It's very disheartening for everyone to see us lose that many guys in one battle, but I stand by the assertion that with decent terrain selection and unit-tactics this type of thing will not happen. When you build a small outpost in an area where insurgents can shoot down upon you, with few to no supporting positions to help you, then the position is asking for trouble. In Kunar, we had observations posts up further on the hills, or even at the very top in some cases, and other mutually supporting positions, just to prevent something like insurgents being able to surround us and shoot down upon us.

Tim Lynch thinks there might be something fishy afoot in the U.S. response:

If my information is correct this story contains a “untruth” told by a Colonel – and that is the kind of thing which really gets me worried. I get worried because I know what happened to our military post Vietnam and would be crushed to see them held in such low esteem and outright contempt by the American public again in my lifetime.

At the end of this engagement Pedros flew in and extracted all the Americans and Afghans from Keating which had been completely destroyed in the fighting. But an Army Colonel quoted in the NYT article said “American forces still controlled the compound, which they share with Afghan security forces.”

Registan.net notes that the Battle of Kamdesh has a broad social context.

Kamdesh is so dangerous and difficult to work in [because] the furthest-flung outposts can only be resupplied by helicopter—and even those face small arms fire during supply runs. The challenge with managing the violence in the area is that, while much of it is performed by outsiders like al Qaeda, most of the HiG fighters are actually locals—a dynamic very similar to southern Kapisa province, where many of the HiG militants in the area are locals either paid to attack U.S. forces or do so simply out of pride for HiG’s role in defeating the Soviet Union.

Lastly, the Canada-Afghanistan blog notes that the purpose behind the attack might have been psychological:

A thought that had occurred to me is that the Taliban are probably orchestrating these attacks as part of a propaganda and psy-ops effort. The Americans have already announced they're withdrawing from those exposed outposts in Nuristan; with attacks like this, the Taliban will claim the withdrawal as a military and moral victory.

There is undoubtedly more reaction to come.