The latest developments in the DSLR cameras shows that it’s quite cost effective to shoot a movie using them.

Here are some examples:
– Reverie by Vincent Laforet
– Vincent Laforet blog  (well known photographer)
– Making of Act of Valor movie  and Hurlbut Visuals  (well known cinematographer)
– NoFilmSchool examples
– Resolve community examples
– The Photoletariat examples
– Philip Bloom – making of Red Tails (for Lucasfilm)
– Adam Westbook examples
– Searching For Sonny movie  (Engadget says this is the first feature to be shot using a DSLR )

However, as those above noticed, the DSLR camera processor isn’t yet very good (doesn’t have enough power) at processing shots in which you have lots and fast movements that’s why the shots could be jerky.
But for relatively static images the shots are very good, rivaling a lot with professional video cameras.
For the sound, you may need separate equipment (even maybe a camcorder just for that).

The DSLR are starting to be used in some high budget movies like Iron Man 2 (the shots at the car race – cheaper to be destroyed eventually).

Here is a list of past, curent and future feature films which are using DSLR.

NOTE: This article was published first by me on Quora.com on Mar 5, 2011