Been thinking about it since the forum has slowed down considerably since launch.  Given launch is always going to have a major influx of users, but the forums seem to be taking a significant hit in threads and comments.  Maybe it is due to the organization, i.e. all the classes having seperate sub forums, and just having everything have its own place, or maybe people get their D&D forum fix from other sites.  I know it will pick up in activity at the start of each new phase and when it launches, but with so many other sites already filling the D&D discussion itch would people really flock to this one over the ones they have been using?

Just had another thought.  This may be better as its own thread, but what if Wizards were to merge other editions into Beyond?  It would probably help to build a bigger subscriber base as there are plenty of people who never moved on from 3.5e.  I know it is a lot of work to add all of that though, not to mention the legal hassles.

I am sure that once the app is complete, the forum will be very active. It needs time, as most things.

By shutting down the forums they moved us to other services. I'd wager that people are happy with those other services. The Facebook Group has an insane amount of conversation taking place daily. Between that and Reddit I personally find my daily intake of D&D is already complete. 

These things take time.  You have a brand new group forming a community, who have yet to create bonds or subgroups within.  Once members start forming relationships with others and sharing game time and/or content with each other, you'll see that consistent post activity grow.

The main bullets that this forum addresses remains speculation until further into beta/launch.  As a 5 day old board, I would say it's doing very well for itself.  I would also suggest viewing the below thread already created on this topic, in order to avoid duplicates responses:

http://www.dndbeyond.com/forums/d-d-beyond-general/beta-testing-feedback/1710-these-forums-have-slowed-down

More features will build and keep a community here.  Sharing builds in the character creator, discussing and sharing homebrews, and active use of this when it becomes a fully-fledged tool that you're actively using each week.

It will draw more people here from those other places if it's done better here, or priced better, etc.  Perhaps slowly, perhaps faster.  But it's well so far in this very early stage of the beta.  

I think the separation of forum categories is a big turn off. All the class forums could easily be amalgamated and thread tags added for each class. That alone would boost discussion. I have zero interest in checking out twelve forum categories for new topics.

In fact, I think a lot of the categories could be amalgamated into more generally appealing categories. It's a bit tiresome to click on each individual category, click individual topics, click back to the main one, etc. There really isn't that much that is specifically interesting about the individual categories to warrant a high level of posting and discussion in them, or to click through to them to check on those discussions. And most of the categories could be filtered by way of title tags anyway if someone was searching for a particular topic.

Beta Testing, Bugs, Support & Feedback could all be one forum (there's a lot of confusion over that already). Story & Lore, Arts & Crafts, Streams & Video could all be made into one category as well. Play by Post & Looking for Players as one category, Tips & Tactics, Homebrew and House Rules and Rules & Mechanics, again made into one. Adventurer's League could also be joined with the Looking for Players category.

There's really just far too much in the way of breaking down categories which in turn breaks down and isolates discussions which in turn reduces participation.

To play Devil's Advocate,  perhaps it does reduce participation but it also offers clarity and ease of access for those specifically seeking information on a certain area.  For example, say I want to play a Paladin in my next campaign, but I have to scroll through all sorts of threads for different classes to find the ones relevant to me - that would really put me off.  Searching for tags would too, given it demands several more clicks which is just time consuming, especially if I'm having to do it each time I return to the forum for new posts on the same subject.

Tips & Tactics merging with Rules & Mechanics I could fully support.  Potentially also Streams & Vids into Arts & Crafts, given that they're all player created art/entertainment of some form.

Quote from VillainTheory >>

To play Devil's Advocate,  perhaps it does reduce participation but it also offers clarity and ease of access for those specifically seeking information on a certain area. 

True enough, BadEye.  You're only starting here, and things will improve from here.

I'm strongly considering adding my own homebrew content, and my homebrew campaigns (A customized version of the Forgotten Realms and my own campaign setting Æthercoil) in D&D Beyond once the program is filled out and will be setting some PbP campaigns here.  (I just hope that you won't charge too much for this service.)

Quote from BadEye >>

I encourage everyone to remember this is Day 6 and there's much, much more to come.

Most of the features of stage one on the beta seems like people already have been talked about.

When stage two hits, it will be alot more action here.

And after stage three and info about prices i think we will see some lively discussions.