A quick skim shows that the new note about trolls turning to stone (citing Grettir's Saga and Helen Buckhurst) [p. 110] made it in, as did a new page of material about yet another version of Denham's list to surface (the earliest one yet) [p. 854]. The notes and citations in Appendix IV: Tolkien/Ransome, have now been straightened out. All the illustrations from the original edition are here, including both frontispieces and all twelve pages of plates, plus one new illustration: two sketchy depictions of Gandalf's hat [p. 901]. I see to my regret that the additions to the Acknowledgments, esp. my thanks to Charles Noad for all his help proofing this new edition, didn't make it in.
This new edition does have APPENDIX V: AUTHOR'S COPIES LIST, which identifies all the people on a list Tolkien drew up when he was trying to decide who to give his twelve author's copies to.* And it includes the ADDENDUM, or 'Seventh Stage': some new manuscript material Christopher Tolkien found and sent me too late for inclusion in the original edition. I've divided this into six short sections:
i. Timeline of Events [the fifteen days following Durin's Day]
ii. Notes on a Parley [detailed description of the Front Gate]
iii. Responses to Queries [some proofreader's concerns addressed by JRRT]
iv. Personae [an interesting listing of Thorin & Company]
v. Runic Charts [details on using dwarven runes]
vi. Feanorian Letters [details on writing in tengwar, including punctuation and numbers]
It's a great pity that the latter two weren't published in the Longmans Green edition of 1966, which seems to have been when the bulk of this was written -- just think how readers in the initial wave of Tolkien mania wd have loved a detailed account of how to write in Elvish (tengwar, that is). Ah well: better late (forty-plus years) than never.
There were also extensive errata that should have been incorpoarated into this new edition that I haven't had time to check yet; with in any luck, we took care of any remaining typos and fixed various small glitches here and there (Langland! Langland! Langland!)
On the whole, I find I stand by what I wrote; this edition adds a little here and there, but aside from a thirty-two page addition of new material it's substantially the same book as before -- just larger and more portable, with many small refinements of detail.
Contrary to initial report, it does not weigh five pounds, 'only' two pounds thirteen & a half ounces (1.29 kg for the metrically inclined).
As my wife said: IT'S STILL DONE. AGAIN!
*I find it vastly amusing that he initially wrote down C. S. Lewis's name, then crossed it off
--not because he didn't want to give him one, but because Lewis already had an advance copy (in order for him to do the reviews). Still, it's amusing.