Well, this is a real shame. I will miss this place with it’s unique combination of emotions, logic and illogic, weirdness and nerdiness, intellectualism and silliness, honesty and trolling. One thing is clear, there will be no substitute. Where else would we have such in-depth discussions about the physics of Mass Effect fields, the energy requirements of biotics, the morality of loyalty, the nature of a multidimensional universe, the socio-political implications of the synthesis ending, the nature of artificial intelligence, the finer points of story telling characteristics or about the meaning of life itself (all in the context of BW games of course)? Where else would we simply trade puns, limericks and songs about BW games?
Shall we do that on Twitter with its 140 or whatever character limit? Impossible. On Facebook, where the casual consumers will barge into our nerd-discussions with mockery and ridicule? I think not. On Reddit, where every conversation is basically a giant quote pyramid (the very thing that was made virtually impossible on these boards for good reason)? I don’t think so. On Instagram and Tumblr, with its pictures? Not the right place. On one of the Wikis, which are information databases, more than anything? We’d just be clogging them up. On some fan-site? It would be the best option but which one to choose when the need of the site owners to make a mark fractures the fan base?
These forums had the advantage that they were specifically made for the community to discuss BW games in depth. They were exclusive in that whoever wanted to participate needed to make the extra effort and register (with their games no less). This “effort-wall” kept the group that was on these boards focused for the most part and allowed even long and complicated discussions. The format of the forum with potentially long posts and multi-quote functionality was perfectly suited to foster the kinds of exchanges that this group wanted and had. At the same time, the fact that these were the official boards from BW for BW customers brought everyone who wanted to discuss BW products together in one unavoidable place: The BW forums. Here, you knew that you had the widest exposure to a nonetheless very focused group of people. None of the proposed alternatives can achieve the same comprehensive, yet selected user base for discussions.
Yes, here we relentlessly criticized BioWare for their mistakes but we also praised them for their successes. Yes, we wanted more interaction with the devs but it never occurred to me that their absence would be used to justify the closure of these boards.
In fact, the reasons brought forth by Conal Pierse are – as has been pointed out a lot here already – neither logical nor persuasive but hollow and quite clearly corporate blabla in a rather lame effort to put a positive spin on an action that nobody outside of the company itself can possibly call an achievement. Be assured BioWare, by closing these boards, you are certainly not improving your community, you are in fact castrating it (but I suspect you know that already).
In fact, I have to admit, if I am supposed to take the announcement at face value, I can’t help but feel personally insulted as a user of these boards, who will definitely not migrate to any of the proposed other platforms. If the spin on this really is that closing these boards will help the community, then the only logical conclusion must be that those of us who used these boards exclusively to engage with BW and other BW fans were somehow making it worse.
Ironically, BioWare’s closure of the forums has a mild resemblance of the catalyst’s logic at the end of ME3: “We are afraid of what might happen if we let this old part of our community develop further, so we will exterminate it to make room for a younger fanbase, with parameters that are more to the standards that we can work with.”
A rather whimsical comparison, maybe, but still, it made me chuckle. 
In any case, for me personally, this will probably mark the end of my engagement with the BW community. It was a pleasure to have so many interesting, funny, enlightening and sometimes downright absurd discussions with you all.
I bid you all a very fond farewell!