Psuedo has posted that Mardek 4 has been postponed.
That makes think
1) It most likely has been started already since it implied he worked on it
2) It will probably be a project he will work on soon
3) He says he is done with a large portion of his other projects meaning that if you he find the time to finish that, Mardek 4 will most likely be next.
4) I see Mardek 4 coming out by around 2014 – 2015. 2016 if Psuedo runs into major problems tho.
It really comes down if he is able to solve the emotional turmoil he is currently going through as I noticed it really influences the amount of work he gets done.