UnrealSP.org

One important truth I'd like to reveal about SP2D is the fact that it was created by a very large team (all members and contributors' online handles will be revealed in the readme) but at any given time only a small part of the team was active (like 1-4 people) and for a lot of times on the later stages... none at all.

About half of the actual members of the team are mappers who have retired a long time ago from the Unreal Community (or at least have gone on to other projects outside of USP.org). The project leader, kea, coded most of the classes used for SP2D but he's also busy with Real Life (tm) concerns now as well.

Given that, pretty much all of the maps were finished at least a year (or two) ago but quite a few were in such a severe state of disrepair since they were made a long arse ways back. The very small group of active contributors, including me, had the task of developing remaining maps (and at one point adding a whole new one to let the map pack itself achieve a higher note) as well as modernizing the old maps that were abandoned as-is by their authors.

In conclusion - the reason for all the delays is because of bad timing, lack of motivation, and lack of firepower (manpower) to bring the pack into a release state.

I and a few members of the team, however, are still hopeful towards supporting SP2D post-release - if it actually becomes at least a little popular. (Popular, in Unreal community terminology, meaning was 'downloaded, played, and finished a full playthrough of by five different people' )