The concept, that is.
Christopher Hitchens eulogizes the passing of this insulting locution here.
The "Arab Street" has long been shorthand for lazy journalists and armchair pundits who would like to sum up the hopes and dreams of over one billion people with as little thought as is possible. It has the effect, as Hitchens notes, of "ventriloquizing the Arab or Muslim populace or of conferring axiomatic authenticity on the loudest or hoarsest voice."
That Muslim populations do not all think alike can be proven by recent multi-party elections in Iraq and Palestine. That they will not be ventriloquized is being shown right now in the streets of Beirut. (Bush would love to claim credit for this, but it likely has as much to do with what happened in Kiev as what's happening next door in Iraq. That said, no man can take credit for the stirrings of human nature.)
The term "Arab Street" has always seemed a degrading one. It implies that there is one Arab (or Muslim) culture where all people have the same education (or lack thereof), the same history and the same desires. As a point of comparison, try talking to someone about the "European Street" or the "American Street" and see how far you get. It's an obvious non-sequitur. The term can only have meaning so long as the people being lumped into it are seen not as individuals but as an amorphous mass—in this case, a screaming mob. (Even the term "street" carries an assumption of unruliness that is not implied when the softer "public opinion" is used, as it generally is when talking about the West.)
The degree to which we in the West choose to see the Muslim world as just that—a single world with a single identity—is the degree to which we are doomed to fail in our attempts to develop relationships with Muslim societies that are not based on power and domination alone, but on the mutual respect between free people.