It falls somewhere between good and ok for me.
My peeves about it:
1) Undead elementals - lame lame lame lame concept. Oh, and it's a lame concept. However the undead elementals are almost exactly the same idea with a different background, as the negative touched quasielementals of 2nd ed/Planescape. And this leads into my next peeve.
2) Not a single book cited in the first few pages of LM as inspiration, or having used concepts originally created by other authors in earlier books. Not a single sodding one. Visages? Created in 'Dead Gods'? Apparently not because LM claims them as its own... That's somewhere between tacky and callous in my book...
3) Orcus was in there, yes... but the detail was a complete reprint from an earlier book. And was that book cited? Of course not...
My likes:
1) Morning Glory, or whatever her name is, is just a very cool and nifty concept for a non traditional death deity.
2) Art. More Steve Prescott art makes me a very happy 'loth
3) Visages (even if the art for them stank) and other previous critters that hadn't before been brought into 3.x