With its $500 million investment in the $12 billion Sprint-Clearwire partnership, Google buys itself a hedge against the possibility that the open access rules it fought to link to the C Block of the 700-MHz spectrum might be flouted.Google last week filed a petition with the Federal Communications Commission seeking to have Verizon commit to adhering to the open access rules that apply to Verizon's newly acquired C Block spectrum. Google said that "Verizon has taken the public position that it may exclude its handsets from the open access condition."

Verizon, according to Cynthia Brumfield on the IP Democracy blog, said on Tuesday that it will abide by the open access rules and that Google is the one trying to fix the contest to accommodate its interests.

Nonetheless, it's clear that Verizon isn't keen to give up its power as network gatekeeper. In all likelihood, the C Block spectrum won't be quite as open as Google would like until the lawyers and the regulators sort things out. And that could take years.

In the meantime, Google will have a preferred position in the Sprint-Clearwire WiMax eco-system, not to mention prominent placement on Apple's iPhone. (Don't be surprised if Verizon and Microsoft, neither of which could be described as fans of open systems, cooperate more closely in the near future.)

"We believe that the new network will provide wireless consumers with real choices for the software applications, content, and handsets that they desire," said Google product manager Larry Alder in a blog post on Wednesday. "Such freedom will mirror the openness principles underlying the Internet and enable users to get the most out of their wireless broadband experience."

The big question -- whether wireless consumers really will have the ability to choose the software applications, content, and handsets that they desire. Will they be able to run peer-to-peer or voice-over-IP applications? Will they be able to use a search engine other than Google?