If done right, this can be quite beneficial for everyone, especially if, as reported, Yahoo! doesn’t try to swallow it and turn it into Yahoo! photos. Yahoo! has the resources to deal with backend stability which would allow Flickr to focus on iterating based on its users - a skill that i’m very in awe of wrt Flickr.
On a completely selfish note, it is my hope that the gang will finally move to San Francisco where they belong.