I am in a different situation than most, as I started my site in October 2006, just as US players were being banned from Playtech, Crypto, 32 Red, and others. The combination of limited options as a US player and my GF leaving the country was what gave me the extra time needed to begin the site. In spite of the Neteller fiasco and other USA issues, my site income has grown each month. After just 4 months, I now make more with the affiliate site than I do with my 9 to 5 (senior dig design engineer with multiple grad degrees from Stanford).
I believe there is still plenty of room for quality sites. And there are still plenty of desired features & content not available, as well as markets that have been ignored for the most part. If it’s something you enjoy, I’d recommend giving it a try.