I don't think pen names are passe at all. In fact, they are an important marketing concern. Where does your last name sit on the shelf? It is good to be next to someone famous in your genre, where lots of folks will go. Like the band Blondie wanted a "B" so they could be near the Beatles. Also, how easy is your name to spell? If people hear about you can they easily Google you? Are there are bunch of other writers with the same last name or is your name so common that search results will return a ton of results that aren't you? Do you write in more than one genre? If so, they may be different enough that you want to distinguish them by author name for your readers (Anne Rice writes under three names that I know of, and Iain Banks adds a middle initial for certain novels). If you write romance novels, it is possible that the publisher will keep your name and have other people write under your name. Plus, once your name gets into the Barnes and Noble database, you are forever judged by the figures in the database. If they are good, yeah. If they aren't, you might want another name for future projects.

Needless to say, I'm not too keen to use my real name.

I'm friends with a couple of people who have published in different genres, and who use different names (and in one case a different gender) depending on the genre.

Nope. But they aren't perceived as being needed as much as 25-50 years ago.

Pen names are great, nom-de-guerres are even better.

Cool potential by-lines for Stacie:

Semper Ferrante
W.R.D. Ferrante
S. Atticus Ferrante
Esmeralda Maria Cuesta-Aragon-de Ferrante
F.X. Ferrante

Just don't use JT LeRoy. Are you familiar with the case? New developments are covered in today's New York Times:

tinyurl.com/2m6y4f