As Ian Mohr writes, last year studios waited about four and a half months before bringing out a movie on DVD. That number has been decreasing since, and "one studio chief predicts it could dwindle to just two months, or even fewer for box-office flops."
All I can say is: Please do this. Of course, it will mean the death of stupid movie theaters but that's fine. Theaters need to realize that they need to sell a premium product, rather than thinking that their product (watching a movie in the theater) is the best thing around by default. Theaters are too expensive (it cost almost $20 for me, Kim, and Allison to go to a matinee last weekend!), and the big thing is that they don't care if you have a good movie experience. I've never seen somebody kicked out of the theater for anything, even after complaints were made. If they put out movies on DVD a month after theatrical release, people will stop going to the theaters unless they can get good service, a better experience, better food, something that sets it apart. The theater is dead, long live the theater.