Yusuf Mehdi is the new number-two for Microsoft's Online Services division -- but, as The Prisoner would be the first to ask, who is Number One?

Medhi, formerly Senior VP of Strategic Partnerships, has shifted his responsibilities from mergers and acquisitions to MSN and Microsoft's search properties. He takes most of the job's marketing and search tasks off the plate of Bill Veghte, the senior VP now focusing mainly on the Windows and Windows Live groups; Veghte picks up a new title, Senior Vice President for the Windows Business.

But Medhi isn't stepping into the top spot for the online properties group, leaderless since Kevin Johnson jumped for Juniper Networks in the wake of the failed Yahoo acquisition. That leader will be...

...announced at some later date, says Microsoft. For now, Mehdi joins two senior VPs tasked with interim division leadership: Brian McAndrews, who manages the Advertiser and Publisher Solutions Group, and Satya Nadella, head of the Search, Portal, and Advertising Platform Group. Until a new Online Audience Business head is hired, the three will report to CEO Steve Ballmer, who's said to be still seeking a high-profile "get" -- internal or external -- for the top spot. A Microsoft spokesperson confirmed to BetaNews Tuesday afternoon that the search is still most definitely on for that person.

It's unclear, though, whether recent company history will rewrite itself to make the failed Microsoft acquisition look like a win as Yahoo's stock price thuds below the $33/share Redmond offered. With the stock market in flux, it may be that Microsoft's appetite for an online services acquisition has been refreshed. It's known that Yahoo's Carl Icahn is encouraging that service to merge with AOL, and rumors abound that a merged AOL-Yahoo would pique the interest of Microsoft once more.

Asked if Redmond would take up the acquisition cause again if an AOL-Yahoo merger goes though, a Microsoft spokesperson offered an emphatic no comment.