Short answer: You can put any lens you want on it with the proper adapter.
Long Answer: Adapters usually sell for $50 - $300 depending on whether they're made in China, Japan or Germany. There is a whole cottage industry of companies making adapters. Because the Sony has the shortest distance between sensor and lens known to man, you can literally put any lens you want on it. Sony could have stopped this practice by requiring that the lens identify itself via an IP-protected electronic interface, but they would be the first camera maker to do that, as far as I know, and they would be shooting themselves in the foot.
The Sony lists at $16K compared to the Canon 5D at $2.5K. According to one article I read, Sony is targeting the RED camera with this [PMW-F3L]. IMO, the reason the 5D & 7D are so popular is the quality vs. cost factor. I'm not sure the same people using (or considering) the 5D are going to march out and spend that much on the Sony.
Sorry, I see you were referring to the Sony NEX-VG10.
I come from using professional broadcast cameras, and I would still prefer the Canon 5D. For one thing, as I understand it, the Sony records at 24mbps compared to the 5D's 50mbps. The Canon looks to be much better built; the Sony looks like it would break after one bad incident.
I certainly wouldn't jump over quite yet...Sony has a great reputation in the broadcast camera area and the really good EX1 and EX3 line but in the DSLR video area I would say that Canon has the most experience.
Still, Sony could have produced an outstanding camera, one well worth considering.
I just don't want to be the first in line to try it but will watch with interest what other users think about the camera when used for real productions.
Using adapters isn't ideal for cost reasons if nothing else. As pointed out in the last response, Data rate, frame rate and compression are other factors that will be interesting to compare. Of course user interface and overall build quality is another huge area.
They just announced another Super35 camera, NXCAM, will be priced more like the Panny AF100. There is room and reason for all these cameras, options are a good thing. I would love the F3 but I would probably have to go with the AF100 because of price alone. Then of course you still need a ton of accessories.
Looking at the specs too, looks like there's no p formats, only interlaced. So that's another reason to stick to the DSLR for now. However, this is a good direction to be taking. If a 'proper' video camera came out to which I could attach my canon lenses, then I'd rather use that that a SLR for the added controllability.
Why, HD SDI, HDMI, XLR in puts, built in ND filters, HD quality LCD with waveform and other scopes. Focus assist. larger form factor, more control over the recording. The list goes on.
Most importantly these sensors are made for video and not stills. They are huge in size, less pixels is a very good thing. No line skipping to get down to 1920x1080. They are not for everyone because of the price but they are far superior in their function and image. This does not render DSLR useless and out of date. Everything has its place.