As a general rule, I can tell you few people in academia take seriously any comment attributed to Indians which are unnamed. They generally tend to be comments that struck someone (usually nonNative) as something an Indian might have said, and over time get more attention if the reposter says "an Indian said it."
A couple things jumped out at me that made me doubt a Hopi elder or elders would say this. Using metaphors about a river being so big that the shore becomes distant is something that's foreign to most Hopi elders living in the deep desert.
And the final line, of course, has become very big since the Obama campaign began using it.
I checked out this the same way I check out to make sure my students aren't plagiarizing their papers off the net. I put the title and then some fragments of the passages into search engines.
Every last source I saw came from either Nuage sites, or environmentalist or peace activist sites that uncritically repeated it. The most famous case was Maria Shriver, who quoted it in Schwarzenegger's inauguration ceremony as governor.
And that final line has been attributed to Maya Angelou and a variety of others, mostly Black civil rights activists like June Jordan.
http://books.google.com/books?um=1&lr=&q=%22we+are+the+ones+we%27ve+been+waiting+for&sa=N&start=10The Quotable Rebel: Political Quotations for Dangerous Times - Page 100
by Teishan Latner - Reference - 2005 - 378 pages
Speech, "God's Judgment of White America," 12/4/1963 We are the ones we've been
waiting for. June Jordan, poet, educator.
Also, Alice Walker wrote a book by that title. She attributes it to Jordan also.
http://www.feminist.com/resources/artspeech/genwom/wearetheones.htmlSome other sources mentioned there was a song from the civil rights movement of that name.