It seems like only yesterday – or almost a year and a half ago – that Yahoo!’s Jerry Yang was named interim CEO of the embattled and fragmented company he co-founded. Taking the helm of Yahoo! following entertainment-industry veteran Terry Semel left Yang awash in the throes of a mishmash of “Web company meets traditional media company” – plus a bunch of Web 2.0 acquisitions sprinkled here and there.

By any estimation, the position he inherited would have been a challenge for even the most seasoned executive. So it comes as little surprise that Yang has announced he is stepping down from the position of chief executive, returning to his role as Chief Yahoo!

Taking the role of CEO in June of 2007, Yang inherited one of the leading Web properties – one that had survived despite the dotbomb market and had continued to make headway even in the ever-growing shadow of Google. It was an entity that was filled with both potential promise and potential pitfalls.

And yet with all the turmoil, Yang put on a brave face and offered an optimistic vision for Yahoo! A vision that promised:

“A Yahoo! that executes with speed, clarity and discipline. A Yahoo! that increases its focus on differentiating its products and investing in creativity and innovation. A Yahoo! that better monetizes its audience. A Yahoo! whose great talent is galvanized to address its challenges. And a Yahoo! that is better focused on what’s important to its users, customers, and employees.”

Today more than ever, that goal seems to have been far reaching if not completely unattainable. Not only did Yang have to deal with an assortment of segmented media properties and disjointed service offerings, but he also inherited a Yahoo! with a slew of rapidly expiring lockups, talent chained to Yahoo! – only temporarily – with golden handcuffs from previous acquisitions of Web 2.0 apps like Flickr, delicious, Upcoming, MyBlogLog, and more.

For all of Yang’s optimism, the ship never seemed to quite right itself before being buffeted by the next wave – or outright storm. A tumultuous atmosphere, a series of dances with potential suitors, a number of ambitious yet quickly shuttered app attempts, and a softening – if not plummeting – economy proved too much for Yang.

So now, we await the next chapter in the tale of Yahoo! leadership, first Tim Koogle then Terry Semel then Yang. Who’s next?

Recruitment for a new executive is already underway. Kara Swisher at All Things D is reporting that, while Yahoo! President Sue Decker is being considered, the role will likely go to an outsider.

Yahoo! for Challenges

What challenges lie ahead for the new CEO? In one word, “many.” Shareholders looking for a rebound in the faltering stock price, employees fearful of losing the purple culture to another entity, and a cynical – if not overly critical – Web community who still waits for Yahoo! to regain some of its former glory.

It’s reminiscent of another organization that – after showing promise in its early years – fell into similar straits and took years of floundering before landing the CEO that would eventually lead the company to success. But even those comparisons are unfair – and unwarranted – at this point. Hindsight being what it is.

So the question remains: Has Yahoo! simply been through too much to continue to survive as an independent entity? Has the acquirer become the acquiree? Something tells us, we’ll know the answer to that question, sooner rather than later.