I'm not sure on this one yet, either. They did Universal's Classic Monsters at the first HHN (Fright Nights), so would they do it again for 19 and not something like 20 or 25? However, your just left to assume classic means the Classic Monsters: Wolf Man, Dracula, The Creature, Frankenstein, and Mummy.
Now, with the new Wolf Man movie from Universal coming out next year, could we have something based around that? with the other Classic Monsters? IMO, I don't want to see them in there OLD way, so can they update them all.. and make them ALL more modern by today's standards?
Then, your right about NLC. They are now classics to most people, but will they do it again so soon? There was the 3 year agreement everyone talked about, however my interpretation of it was 2006 (1st year to get design, concepts, and create the event), 2007 (the NLC event itself), and now 2008 (NLC Hollywood). If you follow that, it's over.. could it be extended? sure.
I'm 99% sure we'll see something Wolf Man related at HHN 19 in some way.