I went trowling through a variant databank earlier and came up with a few more random dip ideas. Of course, some of these are beyond jDip's capabilites for faithful representation, so a lot of the work will have to be diverted to photoshop and good notekeeping and calculations on my part (which have been known to flaw before)
Risklike Diplomacy
All SC's will be randomly distributed among the players, whether adjacent or not. Players pick their units and game continues as normal. Also, units can be built in any owned SC.
Rock Paper Scissors
Instead of all units having a strength of 1, a unit will have an alignment to rock, paper, or scissors (or some other arbitrary naming scheme), and depending on what aligned opponent it attacks, it will get a bonus or deficit to it's strength. (ex. Rock will displace Scissors, standoff against Rock, and can't even cut a Paper's support)
Puppet Government
In addition to the normal players, there is an NPC nation. All players submit orders for their own nation and for the NPC one. The NPC nation's units will act on people's submitted orders either randomly or orders that occur the most frequently.
Winter 1898
This is a way to make fresh start games even more of a fresh start. All players start with one home SC and one unit. One players start conquering SC's they will declare if that new SC will be a home one. Then once they get 3 HC's the game continues as normal. I was considering putting a similar system in BlaDipNES but was worried the game would start off too slow.
Economic Diplomacy
This is kind of like normal NESes. Here, SC's can provide an amount of EP's each year, with capitals providing extra. These EP's can be used to maintain existing units, buy new ones, bank, reinvest into the economy, and sometimes things like spending to actually move units (fuel, ya know), trading units and territories with fellow players, and maybe even bribing the mod

And also there's a victory condition for making a buttload of money.
UN Diplomacy
I read through this one quickly but I think it was around the lines of when a country invades an SC, players would vote whether to recognize the aggressor's ownership. If the majority don't recognize, that guy loses the bonus for that turn. I dunno, it sounded better when i first read it.
SC Construction/Destruction
Instead of moving or other orders, a unit can spend a turn turning the land it sits on into an SC. Or for the Scorch Earth-minded it can also destroy an SC. However this task will be interrupted with a standoff or displacement.
More geographical destruction!
In addition to the above thing, I've seen variants where players can really screw up the terrain with things like flooding land zones, drying sea zones, unmountainizing and remountainizing areas, earthquakes that can divide adjacent zones, and so forth.
M.A.D.
Players can build nukes instead of regular units. These items can't move or give support, but they can be launched to any province on the map and will destroy all within, making it impassable and unusable. Also all surrounding zones will be neutralized for a season.
Twin Earth
This thing is played on two regular boards that are theoretically overlayed onto eachother. The player controls the same power on each board. Units can move between boards but only to that province's twin on the other board. (e.g. spa1 and spa2 are adjacent, spa1 and por2 aren't). Um, the sum of SC's and unit counts from both boards are used for adjudication. 35 SC's to win, lalala.
Um, I think that's it for now. Now to watch Mythbusters.