Wow, funny enough I just did this exact same thing about a month ago.
I based it off of Ogre3D's system as well.
I wrote Squirrel bindings for mine so you could have scripts like:
Particle systems are too much fun.
I've spent so many hours just staring at cool particle effects.
P.S: I wish your screenshots would load. 
Cool
in the version i use i have made a particle definition language where you can give initial params to the system (this also quite heavily based on how ogre does it
). But i to have had plans to use squirrel for adding scriptable emitters/affectors
hmm the imagehost i used must have deleted the pictures.. il see if i can find another one and upload some pics
