Now, I know I'm in a minority, but from a role-playing perspective, I liked the concept that nobles were useless, made demands, and didn't work. Due to a longstanding bug, aside from making their name purple on the units list, appointing a dwarf to baron and such didn't actually do much aside add addition mandates.
Long time players (23a/40d guys) should remember that nobles are supposed to be lazy (as are their spouses). Quiestust found and defined why these guys don't become lazy. With DFHack, and a little knowhow, you can restore this behavior:
Technical Explanation For Layman Terms:
Under 40d, nobles immigrated to your fortress instead of being appointed within, which caused them to be generated with specific professions. Dwarf Fortress looks at the profession to know if a specific dwarf is a noble, and if so, if they should be lazy. When this was changed that baron is appointed from from within, the appointment code does not properly change the profession to one of the specific recognized types to force laziness. This is similar to the long standing Lords loosing their status bug, due to a holdover that weaponlords would live only to fight.
Over time the internal numbers that control profession change, to ones that are non-sensical for nobles (MERCHANT, TRAINED_HUNTER, TRAINED_WAR, MASTER_THIEF, THIEF, DRUNK, MONSTER_SLAYER, SCOUT, BEAST_HUNTER, SNATCHER, and MERCENARY).
Furthermore, the noble system was rewritten without this bit of code being triggered (noble professions appear to work via a different vector (I haven't quite figured this out yet, but its mostly irrevelent for this disuccision). I strongly suspect this is why the Dungeon Master noble failed to function in DF2010/early DF2012 as well, though I haven't tested it
If you want to return this behavior to the game, and make your nobles properly lazy, you must tinker with the dwarven soul. The procedure is fairly straightforever. First, select the unit on the unit list you want to make lazy, and manually clear out all his labors.
Then, in DFHack, type: gui/gm-editor, and switch back to Dwarf Fortress.
You'll get this rather scary looking screen:
Be careful editing anything here, you could possibly break your game or worse.
Move to the profession line, and press enter, and type 105. Do the same for profession2, then press escape to close out. The screen should look like this:
If you look at your now modded dwarf, he will laze about doing nothing like a proper noble.
As an added bonus, if he should otherwise loose his position or die, you get this wonderful gem.
This also has interesting possibilities for mods, since if you leave any labors enabled on a dwarf, they will continue to do them, even if they say the noble will not work.
I'm currently tinkering with other bits of the DF units vector; my current goal is to see if I can get animal caretaking to work by just getting the hospital to handle it (which I realize is weird but actually making animal caretaking work will require a fair bit more work).
NOTE: Just to be clear, I take no credit on discovering how this works, just wanted to write it up incase anyone else wanted to use it in a fort, Quiestust has all the credit for this