I came here because I saw your call for opinions in the RSS feed.
Yeah, the [video's] delivery was abrasive and inconducive to constructive dialog, but let's put that aside for the time being and focus on the salient points. It seems the main complaints raised are about transparency and development pace, so I'll put in my two cents on those topics.
The communication issue I agree with. Frankly, I doubt anyone will respond to this thread saying they'd have a problem hearing MORE about the current state of development. One solution already proposed is to open up an RSS of your git. Another idea is to expand your team to appoint someone to handle public relations. You could also make your development goals, priorities, and timeline a public document.
Alblaka makes a very valid but concerning point that this is just a hobby. As a hobby, it will receive attention from developers when the whim grabs them. We, the users, cannot expect anything more than that. However, I believe that is a strong argument for moving to an open source model. That way, when the whim isn't catching anyone, or the right combination of people simultaneously, or if interest starts to wane altogether, other developers can pick up the slack and drive the project forward. You can still choose a license that offers some protection (although I doubt you'd want to expend any resources defending that license if someone did violate it.) If you had a public bug tracker and public git, anyone could read the bugs, grab a branch, hack on it, and submit their fixes for approval.
Alblaka also makes a good point about the forums blowing up with 'bug reports'. I see a simple fix. Public bug tracker and a new forum policy, and promote some long-time / trustworthy forum members as forum moderators to delete the offending posts and ban as appropriate.
At the end of the day, the only reward for working on any Minecraft mod is ego (fame, notoriety, 'credit', feel-good, etc.) or profit. That isn't a value judgement, it just is. There's no way the revenue from ad-sponsored downloads and/or donations offset the man-hours put in, so that leaves ego. Ego can be just as fulfilled with an open source model, possibly even more-so than a closed model. At the end of the day, nobody can take away that Alblaka was the father of IndustrialCraft, no matter how many devs hack on it.
A selfish (for Alblaka and team) motive for opening up development is that you don't need to feel any pressure from the community anymore. If you decide you want to take three months off to write a novel or tour southern Africa, you don't even need to tell anyone or fret about coming back to hate-mail. If the concern is maintaining the scope and balance of the mod, you can still maintain a steering committee--you could be the Linus Torvalds of IC. How cushy would it be to not have to code at all and just field people's commits?
Anyway, you asked for it, so there's my opinion. Love your mod and thanks for all you do (and put up with)... it's a pretty thankless task sometimes, huh?