They will probably announce some low end compacts like Powershot A or IXUS.
I hope I'm wrong and they announce a sub 300 dollar lower-than-s110-end, Powershot S series compact: fast (f1.8-3.5 or so), 3 to 5 times zoom, 1/2.3" sensor, good 12 MP sensor (but no raw because that will kill their s110 sales). Aka, something like the SX260, but a lot faster and less zoom.