This is the oldest substantial Plaza thread on the board, so I figure it should be used. But anyway. Considering Plaza's host recently suspended the site, most of the users there likely already retreated to Klub, if not Cade and Paint. The best explanation is that the site either hasn't been paid for or failed to comply to some rules/limitations. Let's hope this doesn't turn into another Hub bust.
Turns out the hosting service couldn't be paid for, so the site was terminated. And yes, with the owner stating that he no longer plans to pay for hosting and that free hosting is not a likely option, it is very much looking to be the end of the road for both DSiPlaza and the planned 3DSPlaza.
From what I can tell, Plaza has gone to ruin because of the lack of moderators. And if the website is undergoing permanent format changes from DSi to PC, a significant portion amounting to over 60% of the previous community will be out of the picture.