I would love to do the work to port the camera, but is there a for sure way to know that it can be done?
There is always a risk with newer cameras that Canon might change something in their firmware to make it difficult or even impossible to port CHDK. That happened when they switched operating systems a few years ago for example and when they periodically change how their firmware is stored.
Having said that, the IXUS220/ELPH300HS seems to have been successfully ported so I'd guess that the chances are good the ELPH100 would be do-able as it was launched on the same day.
Is is that the camera can be ported for CHDK just no one has yet? Or is it more like we have no idea how to port this thing? If the answer is the first one, I'll go buy it right now and get to work! 
Wow - enthusiasm. Before you get too excited, do you know a bit about software development - especially C and assembler ? And do you have literally hundreds of hours to spare while you come up a steep curve learning CHDK, the porting process and how things work ? Don't get me wrong, it can be a lot of fun if you like that sort of thing. But its not a "one weekend project" by any means - especially your first time.
