The Analecta Sanctae Hildegardis, in Analecta Sacra vol. 8 edited by Jean-Baptiste Pitra (Monte Cassino, 1882)
contains a large number of sermons attributed to Hildegard. I know of no current English translations of the complete sermons and am unaware of any efforts by the CCCM to produce a critical Latin edition.
Thefore it would be another fun project to produce a parallel translation of these works.
All of Hildegard's works have now been released in the CCCM -- vol. 226 ("Opera Minora") was released in 2007 and fills in the gaps -- bringing together Peter Dronke's edition of the Ordo Virtutum, Barbara Newman's edition of the Symphonia, and new editions of the Commentary on the Rule of St. Benedict, the Commentary on John, etc. Any material ("sermons" or otherwise) that appears in the Pitra edition but does not appear either in the CCCM volumes of Hildegard's letters or in any of the other CCCM vols. of her works should be considered spurious -- and in fact, several scholars, including Kathryn Kerby-Fulton, have already shone that some of the "sermons" in the Pitra edition are "Pseudo-Hildegard".
That said, one of my life-long goals is at least to help bring the Liber Vitae Meritorum and the Liber Divinorum Operum into good English translations, so sign me up to help (though I'm not sure how much help I can be at the moment, being caught in the stress machine known as "graduate school"). In fact, I just had to hammer out a translation of the first vision of the LDO for a talk I gave on it on Saturday (for which see talk my blog: http://nathaniel-campbell.blogspot.com/).
And by-the-by, I am so extremely delighted to find such a thing as this group in existence! Thanks!