I was browsing the NaNo forums in preparation of starting to write tomorrow, and ran across a thread talking about which pop culture references you are and are not allowed to use in your novel (song lyrics are a no-no, just about everything else is fair game as long as you don't go into libel territory). One person commented about how (s)he does not use pop culture references in writing, because if the novel survives for 50 years, the novel might seem dated with those references.
So I thought about it. And my conclusion is that you can't avoid dating your novel. The Tomb, by F Paul Wilson, was written in 1984. It's sequel, Legacies, was published in 1998. There were so many references to technology that was commonplace in 1984 but wasn't around in 1998 (payphones, walkmans, etc), and visa versa, that Wilson opted to rerelease The Tomb after making heavy setting edits. These things weren't the focus of the book by any means--just helped get the reader into the setting, but dated the book.
Classics do it too. They are set in a specific time period, which is clear by the setting. It's part of the novel. Would Romeo and Juliet, complete with the language that they use to speak, make sense translated to modern times? Of course not. But the story remains true. Which is why it has been adapted and modernized, why West Side Story exists. Tangled tells the classic story of Rapunzel, a story that was written in the 16th century (and probably originated long before that). But it was modernized and made more acceptable for modern audiences, even if the setting (a kingdom without technology) wasn't changed much. At the time it was written down, it was something that might've actually happened down the block.
So to say that you aren't going to incorporate your culture of the time into your novel, which is set in modern day American (or wherever) is silly. The choices your characters make, the very people they are, depend on their surroundings. You cannot be a teenager or young adult in today's society and not be touched by computers, or celebrities, or what have you. You cannot ignore the tension between the religious right and the liberal left, or the constant debates over gay marriage and abortion that seem to plague the media. They don't have to be the foundation of your character's actions, but his or her upbringing will affect how they look at those of different race, gender, and sexuality. Or how he or she might react if the nation was attacked by Japan. Or how he or she talks and communicates with others (texting vs phones vs computers, etc).
If you write a good story, there's no reason not to believe that in 50 years, it still won't touch people's hearts. So avoiding references to the year that your novel is written is silly. Instead, focus on making sure that your story can touch people who may not understand the culture you describe.