And since none of the core books (5th Edition DMG, Monster Manual, or PHB) gave any Stat Blocks or specifics for any of the Deities, Arch-Devils, or Demon Lords ..... can I assume that this is being saved for a future release of 5th Edition's Deities & Demigods?
Pretty please? With pulpy blood-soaked Tiamat body-parts on top? 
(Hehe. Tiamat, so far, is the only deity or arch-fiend that was given enough info/stats for an encounter. )
Anyways, this is my prediction, that they are planning to release a Deities & Demigods for 5E. I just hope it's sooner than later.
I don't think that the number of people which find a use for CR 30 (or theoritical higher CR values) stat blocks is significant enough for there to really be a call for tossing a bunch together in a single product.
It seems more likely that they keep showing up as they have so far: 1 per monster book, 1 per full-length campaign that deals with such a being's schemes.
Now, a book detailing more about the religious practices of a wide variety of such being's faiths and cults might have a more wide-spread usefulness to it, but even then what most D&D players need to know about these beings is entirely covered by what little info is present in the core rulebooks.
I agree with some of your response. 
First, I think that you are probably right that there is no current need for DMs to involve deities/immortals who are immsensly powerful (like CR 25 to 30). This is especially true since the new 5th Edition is actually seeing an influx of newbie gamers, or many Old School Gamers like myself returning to D&D after being away for many years. Hence, very few Players will have epic-level characters at this time. But..... but we know that will change as time goes on. As 5th Edition matures, so will a legion of Players who will end up having epic-level heroes. THAT is when there will be a need for DMs to have easy access to the stat blocks of persons like Dispater, Demogorgon, or maybe the stat bocks for An Aspect of Orcus, or maybe the possibility of challenging an Aspect of Some Minor Faerunian deity. Maybe that encounter with the Faerunian lesser deity is not a boss fight, but instead the deity bestows a certain blessing, spell or gift to one of the epic characters. But how do we know what kind of spells and what types of items they are likely to have or give out? We have NO stats on them. No concrete info. 
Any book on this subject should definitely give details om the religious practices and the faiths/credos of the numerous faiths, etc. Definitely agree.
AaronOfBarbaria wrote:
moonbeast wrote:
IF they did a Deities & Demigods 5.0 it would be cool if they:
- Use the same pantheons from the original 1E (yeah, I know Cthulhu and Elric will be missing...dammit :D )
- Remove all stat blocks for gods including HP - they are not just "monsters you can go kill" - anyone foolish enough to go to even a lesser god's homeplane will have their asses handed to them. - - And even IF the god manifested outside their homeplane, PCs should be thankful only half of them died if they tried to kill said god
- Provide all the same info on their speciall attacks, spheres, defenses, etc.
Yeah there is no need.
Like PF filling bestiary 4 with great old ones, waste of pages
I think as already shown a big issue is that some people want a book with statted up, fightable Gods.
Whilst others like me really don't care for that, but would love a book focused around implementing different types of religion in D&D, both "historical" and homebew.
One issue is that the stats for Gods and Avatars In the original Deities and Demigods and Legend's and Lore. Were actually kinda very compact in a way that doesn't work with 5E statblocks.
e.g.
Ares' Avatar (fighter 20)
Ares' avatar appears to be a huge fighter with bloodthirsty red eyes. He is powerfully built and carries a deadly looking spear.
Str 21 Dex 18 Con 18
Int 17 Wis 16 Cha 12
MV 15 SZ 7' MR 25%
AC -3 HD 20 HP 160
#AT 2 THAC0 1 Dmg ld8 +8 (spear) +9
Special Att/Def: After the spear of Ares' avatar hits, it opens a wound that will not stop bleeding until both a remove curse and a heal spell have been cast upon it in the same round. This bleeding causes 6 hp of damage per round.
I wouldn't mind a Deities and Demigods book, (or Legends & Lore .... whatever they want to call it,) but the one thing I've always missed, is the way clerics/druids received special powers for worshipping a god as they did in 2nd Edition Legends & Lore/Monster Mythology. I know that the god descriptions in the Greyhawk 2nd edtion campaign set (From the Ashes,) had this format too. I'm assuming Faiths & Avatars for Forgotten Realms (2nd Edition) used this fomat also. A new D&D/L&L book would be a wonderful opportunity to add some more cleric/druid/ (and possibly Paladin) options with this type of format. This format doesn't HAVE to be the same as the way TSR did it for 2nd Edition, but I think you all understand my idea.
I agree that we don't need many CR30+ creatures, however there are definitely aspects of deities, cultists, servants, special monsters, angels, and templates for monsters that have been touched by the gods that could be added.
My group is playing through Murder in Balder's Gate. When I figured out the metaplot, I asked my DM if there is a way to re-kill Bhaal before he could resume his Divine status.
(Apparently not, alas.)
A powered-down deity - one newborn or just resurrected or whatever - would be a reasonable challenge. Going up against 
or Corellon or Amanuator ... foolish mortals...
(That said, the Epic Table at the Winter Fantasy 2014 LFR Battle Interactive went after SHAR and executed her, punishment for complicity in the murder of Mystra.)