If you want good HD video recording get the Sony A35 DSLT ,this one has the edge when it comes to AF in videos ,Sony SLT are the only cameras out there which uses Phase detect AF ,unlike other DSLR which uses the contrast detect AF ,it also has a the brilliant sensor.
Here is the AF comparison between canon 550D and Sony A55
[media]http://www.youtube.com/watch?v=kHPaVD0pHpQ[/media]
Apart from that even using the LCD to frame the shot the Sony still focuses much faster then rival cameras,