Apple has gotten vigilant in defensive its pioneering iPhone lawn on the exposed frontier of the mobile Internet. But the patent infringement lawsuits against handset creators Nokia(NOK) and HTC  are watching like a warm-up battle before the big showdown with goliaths Google and Microsoft.

Apple is squaring off against “potential heavyweights” that want to make “iPhone-like” devices, says Oppenheimer analyst Yair Reiner in an investigation note. But Reiner advises that Apple may be in for a flogging.

“Together, these companies bring to bear an impressive arsenal of intellectual property, money, and public relations savvy, and with it,the ability to administer considerable pain,” Reiner writes.

The anxiety is that Microsoft’s Windows 7 mobile working scheme has the iPhone’s market in its sights and that Microsoft has a deep contextual in software copyrights to back it up.