Currently the state of contact list accessibility in Miranda NG can be described as usable but not ideal. Various features are inaccessible or accessible in a way understandable to some but not straight forward. I have tested all of the available contact list plugins.
The core, classic contact list: inaccessible due to QT being used. I'm not a programmer, but I know there are accessibility libraries that make things nicer especially now that QT 5.3 is out. May be not worth the bother though, read below why.
Clist Modern: reads names of contacts only.
ClistBlind: al information is spoken, but due to it being rather simplistic and being just an experimental project of Pescuma's back in the Miranda IM days it lacks support for various features available in mainstream clists such as selecting multiple contacts. It also gets a little laggy sometimes. If you could solve these issues, it would be perfect,, but I had this discussion with you where it turned out to be rather hard.
ClistMW: I don't remember what the accessibility there was like anymore, but I believe it was something like this of Clist Modern's, I.e. only names of contacts are spoken.
Clist Nicer: the information spoken is the contact's name followed by its status message. Initially I thought adding an option for displaying the status in a text form would be the end of fun as it supports selecting of multiple contacts etc, but after consulting the idea with other blind users there's a little more work involved. Everything boils down to one simple fact: since Clist Nicer doesn't represent a typical listbox class, screenreaders can't recognise it as such thus for example information about the number of items present on screen as well as the number of item currently focused are unavailable. Moreover, the feature of selecting contacts is accessible as such, but again as there are no standard checkboxes in place, we are not notified whether a certain contact is actually selected or not. While this is not a problem while selecting two or three contacts, mass-selection can be a nightmare. I'm not sure how hard it is to deal with all this but if you by any chance managed to do it, Clist Blind could be thrown away all together, which would be cool in a way: one contact list for everyone, no matter your disability.