“We haven’t pushed it real hard in business, and it’s being grabbed out of our hands,” Steve Jobs said last year. “And I talk to people everyday in all kinds of businesses that are using iPads, all the way from boards of directors that are shipping iPads around instead of board books, down to nurses and doctors in hospitals and other large and small businesses.”

If Apple’s not pushing the iPad into the enterprise market, how is it getting there? Carried in by the rank and file–just as smartphones were. Employees are buying iPads, and other mobile devices as well, and enterprise is increasingly supporting them on the back end and sometimes even subsidizing them, or their use.

In other words, the consumer market has evolved into a de facto evangelist for Apple in enterprise, a lucky development for the company, which is uniquely positioned to benefit from it.

“This trend should mean that the key to corporate success over the long term is being strong in consumer devices that you use everyday,” says Barclays analyst Ben Reitzes. “As a result, the purchase pattern is shifting toward laptops, tablets and smart phones being bought by consumers (all key areas of Apple’s strength), while direct sales of corporate products have shorter and smaller upgrade cycles. We call this trend the “Consumerization of IT,” which benefits companies with strong consumer appeal and customer service reputations….We believe Apple has a large lead in terms of driving this trend, while it presents challenges for traditional PC vendors, in our opinion. We believe the iPad’s success in the enterprise will help Apple make further inroads into the corporate market with other products eventually.”

Interesting, this vision of the iPad as Apple’s Trojan Horse for enterprise, particularly since it appears to be a natural evolution of the consumer market. And if it accelerates corporate adoption of the device as well as other Apple hardware over the long term–well then, it truly is magical and revolutionary.

So while all the attention on who Microsoft is hunting next–after its latest parry at grabbing Yahoo’s search business was foiled once again–has settled on Time Warner’s AOL (see BoomTown’s post on that interest from Monday), it would be a mistake to assume that the software giant is not still aiming directly at Yahoo.

Why?

Because it must, and not only for the reason–to get control of its Yahoo’s #2 search business–that has been much focused on.

It’s also Yahoo’s (YHOO) strong display advertising business that Microsoft (MSFT) is clearly after.

It has been obvious that Microsoft needs to get hold of Yahoo’s search market share to even begin to compete with its archrival Google (GOOG) in the Web’s goose-that-laid-the-golden-egg search business.

But the future hope, according to numerous sources within the company, is to gain a foothold at Yahoo in order to someday take over its much more impressive and potentially more lucrative online display business, which includes ads like banners.

“This is not just about search,” said one source. “It is about scale in all aspects of a market that is going to be gigantic.”

In a way, it’s a reliable old Trojan Horse strategy, getting into Yahoo’s house in search and then moving onto display, an arena which many think will be the real moneymaker in the years ahead.

Right now, search rules in the online ad business, which totaled $21.2 billion in 2007, according to the Interactive Advertising Bureau.

Search advertising, which Google completely dominates, with Yahoo second and Microsoft third, accounts for 41 percent of that total.

Display accounts for 34 percent. In this space, Yahoo is king, while Google has been a minor player, despite its recent purchase of DoubleClick. Microsoft has been trying to muscle its way in too.

Many think the scaling and targeting technologies that are developing and that Google or Microsoft certainly can bring to the table–combined with the relationship business for which Yahoo is famous–is the next killer app to make display dominate.

Google, though it is trying to downplay its overall power of late, is aiming hard at doing in display what it has done in search, especially trying to use its powerful technology skills.

“We really feel we’re in a position to become the world’s largest display ads provider,” said Google’s SVP Jonathan Rosenberg in its first-quarter earnings call in April.

Obviously, Microsoft’s efforts in this arena would be greatly helped by being tightly integrated into Yahoo’s search business first.

So, while AOL’s (TWX) Platform A ad business is also attractive, it still only sits in the middle of the online ad food chain.

That’s why Microsoft is not likely to take its eyes off the real prize: Yahoo’s much tastier high-end display business.

Please see this disclosure related to me and Google.