Netflix shouldn't bother to make their own content, unless they're planning to make content that allows them to bolster their real business, which is building the Facebook of TV-and-movie viewing/fandom.
For instance, if they perceive that certain interest groups are being neglected (ahemstartrekahem), they can make content that allows a new, huge interest group to form. But note that their business is not making a Star Trek
TV series. It's corralling the Star Trek
fans into one convenient place, where they can be sold movie tickets to JJ's next opus, merchandise, books, DVDs, and see promotions for other interest groups that appeal to Star Trek
fans (who might also like Jason Bourne
movies or for all I know, Tyler Perry comedies). If Netflix can convince CBS to take on the burden of making Star Trek
themselves, so much the better. Netflix would only step in and make content if they see opportunities going to waste.
The value to Netflix is not the content, which they give away free, but the sheer size of the audience they can attract, and the intelligence that the audience provides about themselves, which allows for more targetting marketing. (And before anyone objects to this, I'm assuming Netflix will be a great deal more savvy about PR and position this marketing as a benefit to the customers - we're showing you what you want to see anyway - not some scary Orwellian crap. That's just a function of hiring the right people to do your PR, which is the first thing Netflix needs to look into.)