JUDITH WEINGARTEN discusses the Queen of Sheba traditions over at Zenobia: Empress of the East: Questions On the Queen of Sheba's Gold.
PaleoJudaica has been following the (supposed) archaeology of the Queen, as well as other aspects of the Queen of Sheba tradition, for a long time. See here, with many links. Incidentally, and further to Judith's comments, the Queen of Sheba got more out of her expensive visit to Solomon than just wisdom. At least according to the legends in the Kebra Negast she also came away with a baby who became the heir to her throne.
The translation of the Syriac version of The Questions of the Queen of Sheba by Sebastian Brock is being republished in volume one of the texts collected for the More Old Testament Pseudepigrapha Project, along with a new translation of the Armenian version by Vahan S. Hovhanessian. The volume should be out in the autumn of this year.