I read you can only get about 1 FPS with snapshots at native 5 megapixels (high frame rate video only supported up to 2 MP).
I know this is an old post, but just add about the Raspberry Pi camera: If you're willing to live with full HD video (1920x1080) you get 30 fps, and 1280x720 is available up to around 90 fps (or 120 with overclocking). That full-HD output is internally downscaled from nearly the entire sensor, so it can be higher quality than you might guess from a "2 MP" label.
Megapixel count does not tell the full story about image quality. It's a 1/4-inch sensor and is not as good at night as a typical IP camera, but with enough light you can get nice video out of it. Also, if you zoom into 1:1 pixels and compare, I find it is superior to any IP camera I have tried including 3MP + 4MP Hikvision, 4 MP Dahua, 5 MP AirLive, and various other lesser-known 5MP models. The reason is the internal Broadcom ISP was designed for the mobile phone market, where image quality is critical. Not least, the thing costs $25 plus a RPi, so for the same money, you can cover many more angles than you could if your camera costs 5x as much.
PIs are neat little devices!