According to David at the blog "In the Meantime," they may well be. An example of his argument:
1) Denominations are confusing in a post-Christian world and often an impediment to mission. When the larger culture was nominally Christian, we had the luxury of squaring off behind our denominational identities. No longer. Ask the typical person with little or no familiarity with the Christian faith the difference between Methodists, Lutherans, and Presbyterians and she’ll likely give you a blank stare that indicates she’s wondering whether you’re still talking about Christianity. Here’s the sad truth: most people in the various denominations have little sense what they mean and no one outside them really cares.
2) The differences between the major denominations are relatively minor. As much as I love a good real-presence vs. memorial-feast slugfest or round of justification/sanctification truth-or-dare, the truth is most of the denominational differences are not only unintelligible to their own members but, in the larger scheme of things, relatively minor. Across the board the major Protestant denominations share a biblical canon, confess the major ecumenical creeds, and observe the same two sacraments. I therefore can – and regularly do – worship at churches of any of the major denominations and feel not even a quiver in my theological conscience.
Read more at the link.