I did download a BlackMagic RAW video sample file and Vegas edited it no problem. Also there's a lot of hype about the RAW DNG image sequences that is generated from Canon cameras installed with a firmware enhancement called Magic Lantern. These DNG files cannot be edited in Vegas (yet).
Search on YouTube for "OliviaTech Blackmagic" She put out a challenge on a RAW BlackMagic clip which you can download from her website. On her YouTube channel you'll see many edits. You can edit it with Vegas.
Those are not Raw files on Olivia's site. Raw files are .dng. Olivia's are ProResHQ. They are shot in the BMCC's flat profile. They are outstanding in the dynamic range they offer, but they are not Raw.
Vegas cannot edit DNG files. However, Vegas can (sort of) handle the DNxHD (or ProResHQ) files that you have the option to record on the Blackmagic Cinema Camera.
If you shoot in Raw, you must "develop" the raw files for use in Vegas. One way to do this is to use DaVinci Resolve. You can render DNxHD 10-bit 4:2:2 high bit rate or even MXF (without audio) 4:4:4 450 Mbit and then edit these in Vegas Pro (in theory). Alternatively, you can export TIFF files (or even DPX) that can be read as image sequences into Vegas.
Another way to develop the Raw DNG files is to use Adobe Camera Raw via Bridge or After Effects or to use Adobe LightRoom. Again, you can render out a file for use in Vegas Pro.
Currently, I and some others here are having problems when trying to use a large number (say, larger than 20) Quicktime files in Vegas Pro. Like many Vegas Pro issues, it is a mystery as to why some experience the problem and others don't. Specifically, I'm having problems using Quicktime DNxHD files that are created in the Blackmagic Cinema Camera or in Resolve. A small number of files works fine. Vegas Pro just chokes when I try to use too many files.
Again, Vegas Pro SHOULD work witih DNxHD and ProResHQ .mov files (and it does work for me with a smallish number, such as 10, in one project). I just have issues with large numbers of files in the same project.
This could be due to Quicktime and how Vegas Pro interacts with it, but I don't know.
Having said that, I have had no issues with using any number of DNxHD and ProResHQ files in Adobe Premiere Pro. Why some software can work with DNxHD and Vegas Pro cannot, I do not know. Reluctantly, I've started learning Premiere Pro, since it seems far more stable than Vegas Pro and doesn't have as many mysterious issues (never mind that it previews at blazing speed, even with fx's applied). If I could edit as naturally in Premiere Pro as I do in Vegas Pro, I'd never use Vegas Pro again. Perhaps with more experience with it, it will come as naturally.
I also use DaVinci Resolve 9 for color correction of DNG, DNxHD, and ProResHQ (and many other formats). There is a new version of DaVinci Resolve (v10) that will be arriving in the next few months that promises NLE tools. See Blackmagic Design's website for details.
I have heard of others using Avid and Final Cut Pro 7 and X with DNxHD and ProResHQ.
The choices are limited with DNG file editing. DaVinci Resolve can handle DNG files natively (you can play them and color correct them, then export/render). There is a plug-in (Ginger HDR) that you can buy for Premiere Pro that will import and interpret the DNG file and edit "natively" with DNG files. I have not tried it.
Honestly, I have no issues with a workflow in which I "develop" the DNG files by rendering them to DNxHD (or MXF if I want to use Vegas Pro - though I can't get audio with these MXF formats). The quality of the resulting files is amazing. The quality out of the BMCC with DNxHD is also outstanding.
I would be thrilled if Vegas Pro would add support for the CinemaDNG format. Now that the Canon 5D Mark III raw hack has a CinemaDNG output format, it seems like it might be a popular Raw format to support.