[Sir Exxon]

Originally posted by Pirengle the BNM: (...) Can I install ToB, open that saved game, and be able to collect the tears and kill Irenicus before progressing to ToB areas?

Yes, you can.
When you install ToB, the BG2-startscreen will change, and you will have to enter either SoA or ToB. Your save will be in the SoA-part, and from there you can just continue playing, before you immediatly become transferred to ToB after defeating Irenicus.

Or can I import another saved game from earlier in the game (Spellhold) and play through?

You can either continue playing it in SoA, or import the party to ToB, and start from there.

Also, are any new areas added to the game besides Watcher's Keep and post-hell happenings? Like some quests near the beginning of the game or something?

As I said before, when you install ToB, the game sort of splits in two, an SoA-part and a ToB-part. In the SoA-part, the only thing that is changed, is that Watcher's Keep is added. Besides that, there are no new things.
The ToB-part is, well, a part of it's own ( [img]tongue.gif[/img] ), meaning that when playing ToB, you can no longer access any SoA-places, except Watcher's Keep.
So, the short answer would probably be a plain "no".