The standard LABELS and standard LISTS in RR are based on standard VB6 labels -- I do not know if they support anti-aliasing (they may just not support it). For Scroll labels it uses the standard VB6 text "print" function -- I do not know if it supports anti-aliasing. For iLists with transparency (i.e. Carwings' lists) anti-aliasing is disabled because of the required transparency functions performed in the list for display. For iLists with NO transparency the text is drawn using standard DirectX functions, so I believe anti-aliasing would work (otherwise I would have not had the trouble of researching how to disable it for transparency mode). I would also not be surprised if the selected font could play a part on whether anti-aliasing works or not.
For standard labels/lists a new control could be made just to support anti-aliasing, but this could actually break compatibility with some of the existing skins (because it could be hard to mimic the VB6 alignment and positioning for text on labels). For Scroll labels, if I'm do any work on it, I'd change the way it works completely to use a transparency layer concept and this would also require not using anti-aliasing.
EDIT: I've just tested all of the fonts used:
-Standard Labels and Standard Lists DO allow cleartype
-Scroll labels DO allow for cleartype
-Non-Transparent iLists DO allow for cleartype
-Transparent iLists (i.e. Carwings' lists) DO NOT allow for cleartype as PER DESIGN