...since i'm one of the idiot's responsible for that book, i'll respond with some thoughts.
there are a number of studies and writings about introducing virgin queens, none (besides dee's) talk about introducing to queenright colonies to supercede them (most first dequeen the colony). most use cages for introduction.
in addition, virgin queens often emerge into a colony (inside a cage), or emerge in a cage in an incubator.
doolittle talked about introducing virgins....and saw no problem with introducing very young virgins, but was focused on having better success with older (4-10 days old):http://books.google.com/books?id=Vy8pAAAAYAAJ&pg=PA82&lpg=PA82&dq=introducing+virgin+queens&source=bl&ots=mR24gRhSKw&sig=WFCEsgqIbGC4XhVbHMrCKegHxvk&hl=en&ei=yDQeTJWqBoT48Aa00uG6DA&sa=X&oi=book_result&ct=result&resnum=6&ved=0CD0Q6AEwBQ#v=onepage&q=introducing%20virgin%20queens&f=false
i'm currently doing this, but because of several intersecting needs (stocking observation hives for market, making cell raising colonies, making nucs), none at the moment are queenright.
we are replicating dee's methods very closely.....using an incubator and having the queens emerge into 3 dram glass vials (so that the virgins are relatively isolated and don't pick up scents from a hive, from each other, or from a queen cage). i have queens emerging as i type (7 on the kitchen table ready to go into queenless nucs i made up yesterday...another 13 to emerge today, and another 8 in two days).
this round of queens will probably head up the nucs they are mated in...the next few rounds will go into "mating nucs", and we are going to try "accelerated queen rearing" (where one virgin is caged in a mating nuc while another takes her mating flights and lays...once a week the mated queen is removed, the caged queen is released to mate, and a new caged virgin is placed in the hive).
...i know i didn't answer your question directly, but in any case, if you think you have some genetics worth preserving, you should never requeen with a mated queen.
fwiw, if all goes well, we will have nucs (expensive), and both mated and virgin queens available at the conference this year.