I'm voting "Other".
Wether gods or avatars have stats (or neither do) is a matter for the individual campaign. I think that in the D&D cosmology having stats for the gods makes most sense. There are outer planes, and the gods are said to rule them - so it makes sense to treat them as characters. And there would be high-level groups that might want to travel to a god's plane and kill him. I have nothing against that - if that's what you want to do for fan, go for it. However, this isn't what normal campaigns need.
Normal campaigns need two things, IMO: advancement options for PCs (and, to a lesser extent, NPCs), and insight into how the religions operate in the world. I think the two topics are too broad to cover well in a single volume, so I prefer two seperate books (at least) - Complete Divine (advancement) and Faiths & Pantheons (religions from the roleplaying, political, and plot aspect). Neither of these books needs stats for gods, although details on their powers to influence and perceive events would be needed (especially for the Faiths & Pantheons book). In principle, a "Faiths & Pantheons" can include "avatars" or deity stats, as means to intervene directly and strongly, but in practice these kinds of interventions are too high-level and space-requiring to merit the inclusion of such statistics.
A book that presents stats for the deities is another matter completely. The stats would only be useful for a high-level campaign where deities are adversaries. As such, it should be advertised (and designed) for what it is - an epic monster manual. Again, there is nothing wrong with that. But I don't think room will suffice to release a book detailing stats (and perhaps locales) for deific encounters (whether of avatars or the true deities) for a significant number of deities that will still have enough room left to adequeately service the other two needs (advancement and roleplaying/plot). It needs to be a seperate monster-manual, not part of the other books, if it is to be done well.
A third kind of product is for groups wanting to play the divinity game. Like the old Immortals boxed set, giving players the ability to become gods. This is again another sort of product and should be designed to facilitate this kind of game rather than serve as a monster manual. Stats for gods should be limited to a few sample deities and/or opponents at most.
I found the 3e Deities & Demigods a very bad book because it tried to do it all, so ended up doing everything badly. It presented some information useful for roleplaying a deity's follower (such as dogma, religious sects, and so on) or a deity/religion (providing the DM with information of what the deity is aware of, for example) - but not much. It provided some PrCs for the character to advance into or so on - but not much. It provided statistis for gods, but these did not serve well as monsters (they even lacked CR). It provided rules to play the divine game (to play deities), but these rules were clearly not balanced or intended for a fun game of characters as deities. It did everything, bad.