Since Iņigo has stated he's not doing any more development for the DR, I guess this is kind of moot. However, I'll post what I'd like to see in DR800+ v5:
-Optional (registry entry?) removal of 'SysTray' icons to download content and switch Plane mode on/off.
AFAIK we can't set up MyIrex accounts any more, so we can't officially download content to the device, and 3G connectivity was based on long expired contracts and no one has ever brought it to some degree of utility anyway, so these icons are not only useless but an annoyance because I keep tapping on them by accident when reaching for the battery status or stylus ones.
Of course, removing them from the 'setup' panel as well would be a plus, (I know all you have to do is remove some shortcuts from /usr/share/ctb/settings so I'll eventually do this myself) but these are not as big an annoyance.
-'Open with' alternatives a la MackxPatch, so I can open annotated PDFs directly in 'import' mode with Xournal.
-Ability to rearrange (and remove) start page icons - well, in general, porting MackxPatch back to the DR800
@Iņigo, how difficult do you think this would be? - I'm asking just in case I have to do it myself...