the short falls of the camera, firstly the look of it, when you take it to a shoot and you show the client they are like what that? It's a stills camera!!! it takes quite alot of convincing to win them around UNTIL they see the footage. But ill go on to that later...
The second issue is audio the in camera audio is terrible i MEAN really terrible!! but with a 2 tier system (a 2nd audio solution) using my zoom h4n the audio is great. The standard of audio from the zoom is great 4 track recording phantom power with 2 line in xlrs. Down side to the zoom, it eats batteries and is tricky to to work while attached to the camera, if you manually set up the levels you cant see them or ride them during recording so it makes life awkward.
But the biggest problem i have is the post, i do alot of work with fast turnaround times and having to convert all the h.264 files into something usable (usually apple pro res) it takes alot of time. I batch convert using mpeg stream clip which is a great free application but takes a long time 16gb's of footage takes me about 4 or 5 hours on my macbook pro which means that realistically i have to leave it over night. Then there is the audio sync, on small clips its easy but when you get into complicated multiple set ups and locations i end up using a program called pluraleyes. This is a great tool for syncing audio its amazing and its surprisingly fast but when you get to 20+ clips with 4 channels of audio its a nightmare.
Overall though you don't use a DSLR camera for video without knowing its limitations and the one thing that is worth all the hassle above is the quality of the footage. It is mind blowing, i've used so many different cameras in my life from 100k+ rigs to £1000 handy cams and the 7d blows all of them away, the DOF (depth of Field) is stunning but is not the be all and end all of the camera it is the cherry on the top. The DOF is well covered on other sites so i wont wax lyrical about how great it is. For me what is really amazing is how it handles the mundane, the standard head and shoulders interview stuff, the establishing shots and the fast motion. This camera will work in an area under any pressure (except extremely long lens with lots of movement that = jello effect!) with a bit of thought and prep you can shoot truly amazing stuff.
To finish im a big believer in the right camera for the right job, and the 7d will not be suitable for everything but overall this is a great, great, great camera and in two or three generations time canon will have all the problems overcome and whats amazing is that you can already start building your lens collection now.