Coincidentally, I just spent most of Saturday shooting an event using a Canon DSLR and four lenses. I've always had reservations about SLR's as video cameras - lack of auto-focus, difficult manual focus, form factor, etc., - and this experience did nothing to change my mind. Yes, I could get some really interesting and unusual shots, but the problems listed above - as well as the hassle of constantly changing lenses - had me wishing I'd used a regular video camera.
So I'm awaiting the arrival of the NEX-VG10, even though it seems to have limitations too.
Alistar Chapman at XDCAM-User.com got to play with a prototype Sony NEX-VG10 for a brief period of time last week. He found it small and light, though a bit front heavy with the supplied lens. As others have observed, there's no rocker switch for zooming; you use one of the rings on the lens:
With the supplied lens you turn the forward ring to zoom and rear ring to focus. It was quite stiff turning the zoom ring and very difficult to do in shot zooms as you tend to twist the whole camera as you rotate the zoom ring.He said that he saw no sings of aliasing in the clips he shot, though others say they can see aliasing in clips from the camera.
Perhaps more troubling, he found the low light performance wasn't great. This is a concern that others have expressed, though it could be the fault of the standard lens, which is only f3.5. You could always buy the f/2.8 16mm lens they are selling for the NEX cameras, but then you're back to switching lenses...
XDCAM-User.com: Sony NEX-VG10 APS-C Camcorder Launched, available September
B&H: Sony NEX-VG10 Interchangeable Lens Handycam