The Vault is in the process of adding the new projects. Once that is all ironed out the projects on the removal list will be taken out. So don't be surprised by fluctuations in the team standings for the next few days.
 
New Projects
 
MindModeling@Home - Bio/Medical (in the works, having issues with stats exports from MM's website)
Constellation - Physical Sciences
PrimaBoinca – Mathematics
Numberfields – Mathematics
NRG@Home - Bio/Medical (on hold until their new server is up and running)
 
 
Projects on the removal list:
 
ABC
RNA
LHC
The Lattice Project
PSP
Climate Prediction

Maybe it was removed awhile, but why was Majestic 12 removed, but Dimes stayed?

Planetclown is correct, Majestic 12 was removed because they were not accepting new users. I tried to get several of the non Boinc projects removed from the vault but none of the other admins thought it was a good idea. Frankly I want to see all non Boinc projects gone from the Vault since many of them are represented in other Boinc projects. The only non Boinc project I think should stay would be FAH and only because of its popularity and user base.

bcavnaugh

Khalifrio
Planetclown is correct, Majestic 12 was removed because they were not accepting new users. I tried to get several of the non Boinc projects removed from the vault but none of the other admins thought it was a good idea. Frankly I want to see all non Boinc projects gone from the Vault since many of them are represented in other Boinc projects. The only non Boinc project I think should stay would be FAH and only because of its popularity and user base.

5/07/14 Project continues for existing members only
From today we are stopping accepting NEW project members, however the project continues for those who have already joined it!
 
Do most of BOINC Project do this?

No, most project do not do this at all. But the difference with Majestic 12 is they actually pay some people to crunch projects. So they are outside the norm to begin with.

RHMash

Khalifrio

bcavnaugh

Khalifrio
Planetclown is correct, Majestic 12 was removed because they were not accepting new users. I tried to get several of the non Boinc projects removed from the vault but none of the other admins thought it was a good idea. Frankly I want to see all non Boinc projects gone from the Vault since many of them are represented in other Boinc projects. The only non Boinc project I think should stay would be FAH and only because of its popularity and user base.

5/07/14 Project continues for existing members only
From today we are stopping accepting NEW project members, however the project continues for those who have already joined it!
 
Do most of BOINC Project do this?

No, most project do not do this at all. But the difference with Majestic 12 is they actually pay some people to crunch projects. So they are outside the norm to begin with.

Didn't know they stopped accepting new members.  As far as payments go, I get a cents every three months for past work I did with them.  You can make a good chunk of money if you put in the time and resources, but you'll be spending more in terms of hardware, power and bandwidth than you get in return.  And receiving payments is optional.  If it wasn't for being on the vault, I'd have no knowledge of it.  
 
There are BOINC projects that restrict users.  There are only a handful, some do it because they have unique hardware requirements, some do it to limit the number of users when testing, as well.  It's just these projects tend to either be around for a short time because the project is only focused on something that does not require years of work or lose funding or interest on either side.

Most BOINC projects do not limit users or teams. The ones that do as you say are usually during testing phase or in the very rare occasion have hardware that can't support too many connecting or have so little work that it would be pointless to let everyone pile on. I believe Climate Prediction still has a beta site that they restricted to invite only. That was done mainly because their work units take so long to run and testing is terrible when you have people not finishing work units because of aborting or won't give any details on their findings. So, you will find that the DC-Vault will not add projects that do this. Thus the reason for the rule to be added that states the project must not limit users or teams. If a project is added and later violates those terms, it will be pulled just as MJ-12 has.
 
As far as getting paid at MJ-12, you may want to go to their forums and have a look see in the General category. You will find that they are changing that up and actually have a whole different forum set up for those qualifying for payouts. (clue: you are now a partial owner legally) Details of the future payouts aren't locked in stone just yet, and not much has been said whether you can raise the amount you receive beyond just improving the overall success of the project. Before it was tied to your contribution. Now it seems like it will become tied to the financial success of the company and your "shares" are pretty well locked.
 
Edit: http://www.majestic12.co.uk/forum/viewtopic.php?t=5251