There are plenty of threads on this, a new one was unnecessary, but here is a brief summary of my previous posts on the matter.
1. GeneralEtrius is ncorrect. We have been assured multiple times by Stardock that Brad is working on an updated manual. There is a .pdf maual included with the ToA package entitled Twilight of the Arnor Manual, but it is merely the old Gold Edition manual with a new cover page. This is annoyingly deceptive even if you think, as I do, the deception is not intentional but merely someone setting up a revised manual, not following through due to time pressure, etc., and forgetting about it.
2. A revised manual, including things like the new tech tree, is needed and should have been available at release. However, Stardock has indicated (wrongheadedly IMO) that such information is more in the nature of a strategy guide. This mindset may partially explain point 3.
3. Whether or not a revised ToA manual sees the light of day is, unfortunately, probably meaningless. Stardock has an unbroken track record (GalCiv, Sins, PM2008) of producing terrible manuals and ingame tutorials. They are poorly organized, very incomplete, and often vague about what is included (possibly due to the mindset noted in point 2). That a manual can be done right (and by a small company) is demonstrated by Stardock's most similar competitor, Paradox. They have produced excellent detailed manuals for their recent games, and the two expansion packs to EUIII have .pdf manuals stating the changes and additions in very detailed and precise terms. Stardock's documentation looks even worse compared to the excellent documentation of Civ4. (Granted, Firaxis certainly had a far larger budget for that game than Stardock does, but I am not sure that excuses the poor manual. Especially when the Civ4 manual is not merely better than that for GalCiv, but better by at least a factor of ten.). More damning to Stardock is the cult fantasy TBS game Dominions 3, developed by a two-man team and published by niche publisher Shrapnel Games. Dominions 3 includes an excellent and detailed 292-page ring bound manual that comes complete with a great walk through tutorial, myriad charts of spells, units, items, factions, and even an index. Granted, that is likely why the intial price was $55, but I'd gladly pay an additonal $5 or so for a similar GalCiv manual. (Please note, that I still think GalCiv should have included a far better manual than it did at no additional surcharge.)