basically, instead of all your particles being erased, it goes into the bin. this will remove all ctrl-z problems and will be pretty cool. to access the bin, press a button. it pops up on screen and it will be tiltable and moveable. there will also be an empty function.
What CTRL-Z problems? There are no problems with CTRL-Z. It functions as it should.
As for the idea, I don't see the point. Can't you just locally save it? Or save it to the server every time you do a major update, then go back through the history or reload it.
There is a undo function in place (Ctrl Z) that has a single history, this should be god enough when creating particles, if you want a larger rollback history or more reliable backup, I suggest you use stamps.