I sent off the email earlier and received this as a reply (hope the sender doesn't mind, there's nothing particularly personal about it but I can't say 100% for certain that's it an automated reply, and it probably isn't):
Thanks for your interest in our next edition. As we have one reseller of the publication, Amateur Electronics Supply in Las Vegas, we attempt to coordinate the new edition with the approximate date that they will be out of stock of the old edition. This is balanced by the amount of changes, new information, etc that is available for the new edition. In the past our average time between editions has been seven months, but this time it will be a bit longer. Our logical guess for the next publication release date is Feb 2008.
The new edition will have many updates including new maps for the LVMPD and NLVPD.
Henderson PD has been less than cooperative in this matter.
Anyway, thanks for the e-mail and be sure to monitor on New Years Eve, the best time to listen to the locals every year.
Soooo... obviously I'll be listening. The Clark County FD was doing a massive exercise today on TGs normally assigned as NYE (New Year's Eve) TGs so, guess things are getting ramped up for all the action in a few days.