The Register had an interview with Opera Software's CEO Jon von Tetzchner:
Andrew Brown, a big fan of Opera, wrote that he chose to move to FireFox because it was more compatible with new websites, partly citing Flickr compatibility. Do you feel you're falling behind?
We've always been moving in a space where people come up with their own ideas all the time. Now Netscape 4 is out of the market, so compatibility with that isn't so important; IE6 is fading, while IE7 has more compatibility - does that mean problem has gone? As people make more and more applications we see more and more standards. IE in particular has its own stuff, but that's part of the reason us, Apple, and Mozilla work on submitting new standards to the W3C, and getting them adopted. So we're quite optimistic.
It's a chicken and egg situation, which means we need to get more users. And we are. We have by far the most used mobile web browser. Net Applications' survey is showing Mini as the fifth most used browser in the world and in some countries it's beating Safari, and others it's beating Mozilla. The Nintendo Wii is also helping and we're working on new version coming out.