When will be the New model of Canon 550D coming?

I was thinking to buy Canon 550D or Nikon D3100 but i was thinking that Canon will launch his new model of 550D, So should i wait or buy this one only?

While there's a lot of pressure on Canon to include auto-focus on their entry level 500D series cameras, the typical technical advancement cycle of dSLR's tends to be from 18 months to two years.

The 550D is relatively new, out about 6 months

Many Canon users had hoped that the new more advanced 60D would have included auto-focus in the video mode.

Maybe we will see that in the next cycle

Some people favor auto focus in video but many do not. The reason is simple. I, for example, have two video cameras - one is older the Fuji 9000.It's a bridge camera will nearly full control that also does video. Given the technology of the day it does an excellent job but, having auto focus in video is bad because as I shoot people moving about the focus tends to swing wildly at times causing the entire picture to go out of focus while the camera searches for focus.

On the other hand I also have a Canon eos t1i without auto focus in video. With this camera that focus swing doesn't occur and the picture is rock solid. Not counting the HD video it's much better, at least for me, because my video is stable through out the recording… Much better all around.