My company was an early adopter of shooting video on Canon DSLRs (5D2, 7D, then 650D, 70D...) and invested a lot of money into this for great results. But now our cameras are looking like Ford Model T's compared to the Ferrari's coming from other brands (Sony's A7S, Panasonic's GH4). It pains us to see Canon so complacent in an area that they pioneered. Now it's not even an option to stay with Canon. For less money we can get much better video with the GH4 and A7S, and we're going to switch soon.
Some may argue that these DSLRs weren't made for video in the first place. That's sour grape talk. Look at the huge market of video accessories that the 5D2 created and tell me it's not a segment that's worth exploring at a competitive price point.
We'll still stay with Canon for stills since there are no complaints there. But there are clearly better options for video.
Canon didn't abandon their video market at all. They have the most successful line of cinema cameras going (no, I don't have sales figures, but based on what I see at and hear from rental houses and owner/ops). The C300 is very affordable but if you are looking to buy multiple bodies the C100 is ok, too...
I don't see why people think Canon has abandoned this market. They haven't at all. The video quality on the next round of 7Ds is irrelevant, although they will be used as b cams, because they are already good enough for broadcast for stealing shots. The majority of the broadcast market will go to Arri with Canons on the low end and as additional unit cameras.
The video quality of the C500 successor and C300 successor will be what to watch... this is where Canon's "cinema" video market is and if the C500 is excellent they might be able to reclaim a bit of market share from Arri, which controls both broadcast and theatrical.
The C100 is the low end of its owner/op market, displacing the 5D II, which accidentally catered to this market, and is popular for wedding videography and low end corporate/web.
The A7s and GH4 are probably fine hybrid cameras, but it seems odd to switch when Canon has the healthiest ecosystem and best (and uniquely, delightfully single-purpose) products and by far the cheapest professional cinema camera with the C300. (The F5 is not cheap!)