For no particular reason, I've always been a little obsessed with baby names. Anyway, I was looking online at the top 20 baby girl names from the 1920s and they were the following:
Mary, Dorothy, Helen, Margaret, Ruth, Mildred, Anna, Elizabeth, Frances, Marie, Evelyn, Virginia, Alice, Florence, Rose, Lillian, Irene, Louise, Edna, Gladys
I treat a primarily geriatric population of patients and I can absolutely say this is accurate. Literally every other patient is named Dorothy. I can often guess the age of a patient (give or take five years) based on their first name. Some of these names are sort of timeless, like Anna. But others, like Mildred, are incredibly dated. Both my grandmothers' names are on that list.
Now look at the top 20 baby names of 2010:
Sophia, Isabella, Olivia, Emma, Chloe, Ava, Abigail, Madison, Ella, Addison, Emily, Lily, Mia, Avery, Grace, Hannah, Elizabeth, Charlotte, Zoe, Natalie
Notice there are only two names in common from both lists: Elizabeth and Lily/Lillian. (Although I've noticed that old Elizabeths call themselves Betty/Betsy and young Elizabeths go by Liz.)
Now as a person who lives in the year 2011, I think these names mostly sound pretty cute. (Except for Addison, which just reminds me of JFK's orange complexion.) Once again, some of those names are timeless, but I guarantee that in 70 years, Madison will probably call to mind an elderly stroke patient. (Sorry if your kid's name is Madison. Or Addison.)
You could say similar things about male names, but they tend to be much less trendy, from what I've observed. There are a lot of Joes, Johns, and Jims no matter how old the man is.
Not that I think anyone would actually take this post into consideration when choosing their kid's name, but how the name will sound fifty years from now is something to think about. After all, even 40 year old Kid Rock is regretting his name.