For those citing Colt's place as a niche maker, have any of you looked at their actual production numbers as opposed to other competitors in the niche revolver market?
In 2010, Colt produced only 2,086 revolvers while U.S. Firearms, their closest competitor in the niche SA revolver market, produced 12,007.
At 2,086 revolvers per year, Colt has basically become a specialty custom gunmaker like Les Baer, Wilson Combat, or Ed Brown with similar production numbers. Successful specialty makers like Baer, Wilson, and Brown are able to remain profitable despite their low production numbers because the specialize in just a few basic gun designs thus simplifying their production. Colt has also chosen to do this by paring their product line down to AR-15's, 1911's, and SAA's.
Adding DA revolvers back to the line would complicate things and drive up costs in several ways. Most, if not all, of the Colt employees who produced and were familiar with Colt DA revolvers have either retired or passed away. This means that not only would new employees have to be trained for a completely new-to-them product, but that there are very few people left to teach them.
Secondly, the machinery necessary to build DA revolvers is most likely long gone. It is doubtful that Colt has kept old, unused machinery sitting around gathering dust and taking up space for 10+ years and, by many accounts I've heard and read, the DA revolver machinery was getting rather long-in-the-tooth when production ceased. This means that Colt would likely have to invest in new machinery which would be extremely expensive.
You see, at this point it would not be a simple matter of firing up the machines and resuming production. At this point, they would basically be starting from scratch all over again. Even if Colt could make such guns profitably, which is arguable, it would still require a very large intial investment that I just don't believe Colt can afford to make right now.