"There should be some tangible developments for the community around the week of May 1st."
Any updates on what that might be, or do we just need to wait?
From what I know all we have left now is to wait :p
But not too long

the first deliverable is well under way and I'm free all week with it being my primary focus.
Is BTM dead? We haven't gotten any updates in over a month. There's no news on diff algorithm change. Someone dumped 25k BTM on Poloniex, taking a shit on the price. The only activity in this thread now is people trying to sell what they have before they lose it all.
Is there any active development going on? Can we expect updates? Can we expect marking to be released? Can we expect any news at all? Or is this the end of the line for Bitmark?
It's not dead, people are still around. Mark is currently in a bad situation but is getting it sorted out now. Medic and Neleonele are in contact with him frequently, probably on a daily basis.
The multi user wallet app is
supposed to be done or be very close to being done. I'm not sure exactly.
Everyone should be aware that things have been promised multiple times on slack but nothing was delivered. The developer Nathan aka Mark Phenig aka coinsolidation has not logged in to slack for a long time and no code has been uploaded to github. I'm not sure if any code even exists at this point.
I heard that Nathan/Mark was forced to leave his previous home and was effectively 'homeless' for a while. In those circumstances I think it's unreasonable to expect Mark will be doing much coding. It's also reasonable to assume that Mark will have had some time to take stock of his current situation and how he ended up there, and I can imagine he'll be putting 100% of his energy into lifting himself out of the hole he's currently in, and part of his recovery plan and 'redemption' will probably include BTM.
I was homeless and living out of my car for a while not that long ago, and as the cause of my homelessness wasn't drugs/alcohol, and my mind was exactly the same as it had always been, I found that I stripped away every piece of unnecessary baggage in my life (mental & emotional) that could become a potential distraction to my number one goal - getting back on my feet financially and in control of my circumstances again. Life was incredibly difficult at times, but the will & determination I had to get 'back' created an incredible mental clarity and drive that I had never experienced before, and I now see that experience was a blessing in a way.
I became so hungry for success, and I achieved it, and quickly too. I don't think being homeless while battling drug & alcohol addictions would have the same effect, but from my experience being right on the edge of the abyss while still having your mental faculties intact is THE supreme motivator to discover what really drives you forward, and what your life goals actually are. That's what happened to me anyway, and I hope Nathan/Mark experiences something similar. If he does, and if bitmark features in his new battle hardened set of life goals, then I'd expect BTM investors 'might' be rewarded for hanging in a while longer with this project.
Good luck Mark!!