The man with responsibility for navigating the choppy waters of Microsoft’s battle with Google opted to head for the lifeboats. Long-time executive Johnson wrapped up 16 years with Microsoft and headed for network hardware maker Juniper.

Microsoft said in a statement Johnson’s old Division would be split into two groups: Windows/Windows Live and Online Services, both under CEO Steve Ballmer. A trio of senior vice presidents will head the Windows Live side.

As for Online Services, and the duty of trying to find a way to carve out some of Google’s share of the online search and advertising markets, Microsoft plans to create a new senior leadership role. Satya Nadella, currently running the search, ad, and MSN engineering efforts, apparently will stay in that position and report to the new lead.

Johnson held a prominent role over the past few months with regards to Microsoft’s failed attempt to acquire Yahoo. All Things D said he served as the point person for those negotiations, which ultimately ended with Yahoo signing a search advertising deal with Google.

All Things D also cited the internal memo from Ballmer to Microsoft regarding the latest reorganization, and Johnson’s departure. Ballmer told employees the Yahoo takeover attempts were “a tactic, not a strategy” to expand Microsoft’s search and advertising share.

“Search is the key to unlocking the enormous market opportunities in advertising, and it is an area that is ripe for innovation,” Ballmer said.

But, hey, at least it’s on the upward part of the journey.  And in some circumstances, “exploding” is a desirable result – a person’s popularity can explode, for example, and so, presumably, can a search engine’s.  I’ve got to figure that’s the sort of thing Johnson meant, as opposed to the idea that Microsoft would become a fiery bringer of death.

The nonviolent interpretation also meshes well with the rest of Johnson’s comment to Reuters.  “Over the next 12 months, we’ve got a very aggressive engineering plan with multiple releases of search coming forward,” he said.  Well, the “aggressive . . . multiple releases” bit doesn’t really take us that far from the idea of rockets, but I’m still not prepared to think of Microsoft or Johnson in a military sense.

Johnson, by the way, serves as president of Microsoft’s Platforms & Services Division, and, according to the Redmond machine, “has overall responsibility for product development, marketing.”  Furthermore, he’s been given oversight of Microsoft’s new Advertiser and Publisher Solutions Group (“oversight” in the sense that Brian McAndrews, CEO of aQuantive and head of the group, will report to him).

But by any interpretation of the “upward trajectory” comment, Microsoft’s search business will bear watching in the months to come.  If you hear a whistling noise, just remember to duck.