What about background detail in 60D? (look at footage please)

I have the 60D for 2 weeks now and yesterday I went to the forest in to shoot some test footage.

What I noticed in the both selected and unused footage, is that the the object I'm focussing on close to the camera, can be really sharp. (if only I had a z-finder/monitor and a tripod :P)

But the trees that are further away, even when focussed on 'everything', are lacking detail and are in my opinion not sharp.

Please look and judge for yourself:

http://www.youtube.com/watch?v=yZHCq9aTGrI

Is it because of my high aperture (almost all shots arround f 3.0), the lens, something else?

Thanks!