Now. I don't mean that Wonder Woman has never had sex or should never have sex. But I do think there's something to be said for using a different definition of "virgin" when considering the Amazon, a la Marilyn Frye. In this meaning, a woman may have sexual relations but, if unmarried or unpartnered, is considered a virgin, she who is without fetters, not under anyone's control: the willful virgin.
(she dates herself...)
This is the light in which I prefer to read Wonder Woman, for several reasons. First, this definition allows for same-sex relationships, which is useful for people who read Diana as a bisexual or lesbian woman (as I do). Furthermore, it allows for a woman having multiple sexual partners or no sexual partners, according to her lights. I like this because I view Wonder Woman as loving both men and women--but chiefly women--and also as having no particular interest in long-term relationships. Part of the reason that I find the new Superman/Wonder Woman As Official DC Power Couple so distasteful is that I don't see much in Wonder Woman's persona that is interested in being with one person. Her love goes elsewhere; it can be directed to a child in need of help or whole countries. She loves everyone, as a goddess loves. And like a goddess, she might take a consort for some time, or she might not.
Taking her original origin (I am also serenely ignoring her new origin), Diana is gifted by the Greek deities to be "as beautiful as Aphrodite, as wise as Athena, as strong as Hercules, and as swift as Hermes," as well as receiving other blessings from deities such as Demeter and Hestia. All told, these gifts combined with the love and will of the Amazons create a demigoddess who is very similar in many ways to the goddess Artemis, and even shares her Roman counterpart's name, with Artemis and Diana being two of the most well-known virgin goddesses. Pre-Olympian stories indicate that Artemis occasionally loved humans; the stories of Orion, Endymion (where Artemis and Selene are considered to be two parts of a tripartite figure), and possibly Actaeon fit into this scheme, as do the numerous nymphs and maidens Artemis had about her as companions and supernatural/divine versions of Sappho's colony on Lesbos. The pre-Olympian Artemis is the quintessential willful virgin, and as her avatar on Earth, Wonder Woman is too. Both are active, powerful, complex female figures whom misguided souls attempt to cram into too-small boxes.
(...but always diplomatic, even in war)