Kathy, I am a photographer and I am very familiar with copyright. I have also done a lot of work under federal contracts so I'm familiar with copyright in that context as well.
Your post has a headline, "White House Makes Full Copyright Claim on Photos." This is very simply untrue. Think of the ways people assert copyright: using the © copyright symbol, registering works with the copyright office, filing an infringement suit, etc.. I don't mean to say you need to do this to have a copyright, but to say that the White House is making a claim to copyright without doing any of the things we normally do to claim copyright things is misleading at best.
Claiming that works like the ones on Flickr cannot be used for commercial purposes is not claiming a right, but rather stating a fact. The statement is unnecessary, but it seems the White House decided it would be a good idea to remind people of the facts in light of recent events.
The only part that is a little baffling is the statement that the images may not be modified. It's also strange that this is not on the http://www.flickr.com/people/whitehouse page but only under individual images. I'm not sure what they are basing this on, but is certainly does not constitute a "Full Copyright Claim." It seems that the headline and article is written, not to illuminate or inform, but rather to garner attention and be provocative regardless of the facts.