LinkedIn does a lot of things very well. And the quality of their news feed has improved dramatically in the past year.
That said, it's pretty clear that the folks driving their product strategy either don't use the service or don't understand how and why others use it.
The primary uses for LinkedIn are for sales, business development and recruiting. And for all of those functions, change becomes a key trigger. Someone changes jobs or gets a promotion - that creates new opportunity. And LinkedIn ALMOST gets it. They added a feature to notify you when one of your contacts has a change. And even gives you a one-click option to "Congratulate the person on their new role". That's all great...
Except that, in my experience, about 60% of the events LinkedIn thinks are a job change, they're incorrect.
Sometimes, it's just someone updating a small part of their LinkedIn profile, perhaps changing a word in their title. Other times, they've added an additional role, which is not their primary job function. In today's world, many of us have multiple roles. My primary role is as VP, Product Strategy for Connotate. Yet, I also sit on the boards of a couple of nonprofits and trade associations. If I happen to add that fact, I don't need it to appear as though I've just landed a new job. And a dozen of my friends don't need to be embarrassed by incorrectly congratulating me on what's not really a change at all.
And it's not that difficult to fix this.
First, when a user edits their current position or adds a new one, LinkedIn can simply prompt "share this as a new job to your network Y/N?" That would allow users to determine whether that change should be showcased to others. That simple change would diminish the false positives that are currently generated and dramatically increase the value of the change notification. In an instant, they would go from spammy noise to valuable intelligence. And it's not as if LinkedIn couldn't already know that this is not a new position. After all, they list right on your profile how long you've been in that position.

While they're at it, LinkedIn should also fine-tune their approach to endorsements. The endorsement idea is smart. While everyone's fighting over the social graph, they've quickly amassed a "skills graph" which will be highly valuable to recruiters and others. But its value diminishes if it's perceived to be inaccurate. There are three quick ways in which LinkedIn can solve the endorsement noise issue:
First, stop suggesting auto-endorsements to users. The one-click approach to endorsing a person, or worse, a group of four, for a category that LinkedIn suggests, e.g. "Does Bob Smith know Analytics?", does absolutely nothing except pump up the numbers for the skills that are already ranked #1 or #2 for that person. If you want me to endorse someone, lead me to the normal endorsements section, where I can pick out the skills that represent my experiences with that person.
That brings me to number two. Limit endorsements to those people who have a relationship to that person. You're LinkedIn. You know whom I know professionally. So don't have others, who've never worked with me, endorsing my skills. And to make it even more valuable, why not weight endorsements based on relationships. Did you work together? That endorsement might mean more than if you just know each other casually.
Last, stop emailing users to tell them who just endorsed them. That just perpetuates an endorsement circle jerk. It's like the early days of blogging where people felt obligated to add to their blogroll anyone who added their blog to their own blogroll.
LinkedIn has done a great job of dominating the professional social networking market. And, they've also figured out great ways to monetize it. But they need to better understand how people use their platform. And they need to resist the impulse to push more and more noise into the news stream.