The A1400 replaces the A1300 and changes very little - same 28-140mm lens with no image stabilization and 720p video for $109.
The A2600 replaces the A2300 with the exact same features for $149.
The ELPH 130 is closest to the A4000 in shape size and features, (28mm, x8 zoom, 720p) but adds wifi connectivity for $199.
The N is a weird new creature with a box like design, wifi, flip screen (which is half of the camera body) and touch controls, 28mm & x8 zoom. Unlike the other new models, has a CMOS sensor and 1080p video for $299.