I sent a email back in October to Stephen Stringer at the ARS/USDA in poplarville, ms and here is what he sent me
"Several nurseries are taking orders for these. One, Island Grove Ag Products, Hawthorne FL. may have more plants being propagated than some of the others. Their phone # is 352-4815558. Duartes Nursery in CA is also working on micropropagating DeSoto, and may be a good source of plants. Another source you might try is be Ambers Blueberry Farm in Waynesboro, MS (601) 735-4840"
Here is
http://www.duartenursery.com/ and
http://www.islandgroveagproducts.com/index.html also check out there new southern highbush selections "Gupton" and "Dixieblue". I have ordered a few cuttings of Desoto a couple weeks ago like you but have yet to receive them but have had very good luck with getting blueberry cuttings to root. Sometimes it takes a while. Between the two of us if I get them to root I will send to some more cuttings to try. I have numerous cultivars for you to try. I also ordered some of these
http://www.ars.usda.gov/SP2UserFiles/person/1718/PDF/2007/EhlenfeldtandFinnHortScience2007.pdf