Post by totemmunkey
Regarding class specializations and the spellbook, once you choose your spec the spellbook will show only what you gain from that spec, and some specs now lock out certain abilities you were probably used to being available in all specs.
For example, as a warrior Slam used to be available in your spellbook regardless of your spec. But since Slam has been removed from the Fury attack priorities (I try not to use the term rotation anymore), the ability is only available in Arms and does not appear in your spellbook if you choose Fury or Protection. This simplifies things and eliminates the possibility of the uninformed using a spell/attack ability just because its in their spellbook--even if its not optimal.
I'd also suggest checking out the
Wowhead Talent Calculator and clicking on the specs to see this in action. The list of abilities will adjust depending on the spec you highlight. It's a good way to see what's now available to you in every spec before you commit yourself to one.
Regarding talents, they are no longer tied to your spec meaning you can have the same exact talent set regardless of what spec you choose. Talents are also more like glyphs now, in that they are no longer "set & forget" (unless you want) and its encouraged to change them based on what best for the situation. You can also change one talent at a time now (using same reagent need for changing glyphs), instead of resetting them all at once. However that option is still available to you via Class Trainer.
Prime glyphs are gone and their damage boosts have been adjusted elsewhere automatically. Blizzard felt they were boring and didn't really add to player choice. Major glyphs are now where many of the "old talents" have found a home (for instance, a Restoration Shaman's
Telluric Currents and
Cleansing Waters). Like the new talents, you're encouraged to change them to fit the situation. Some classes have more fun/useful major glyphs than others (on my DK, I only have 2 major glyphs equipped; I'm not concerned with leaving the 3rd empty) Minor glyphs are fun mostly cosmetic changes such as a Warrior's
Blazing Trail or a Death Knight's
Geist. Other minor glyphs affect abilities for convenience sake such as an Elemental Shaman's
Thunderstorm or a Death Knight's
Army of the Dead (tanks in PvE groups especially appreciate those two).
Welcome back to WoW, and don't get overwhelmed with the amount of content available in Mist of Pandaria. I recommend going at your own pace and only do what you
enjoy doing. After all, its a game and games are meant to be fun!