Well I started using the new Yahoo Mail Beta today on my home computer and it is awesome! However alas, it is not supported on Opera and when I tried to use it on my 770 it said, "This browser is not supported" and then listed the four that were!
I've run into several sites that "do not support Opera." I can see this type of problem cropping up with certain sites like Yahoo Mail Beta, because they are using AJAX (even though GMail seems to handle everything fairly well).
What I don't get is sites that don't support Opera for no reason in particular. Before I go any further, I just want to say I'm no Opera fanboy--I use Firefox on the PC. I did all of my Christmas shopping from the 770 this year. I ran into several ecommerce sites that would allow me in because Opera is not a supported browser. This is the stupidest thing I've ever seen. That's like walking into a store and someone stopping you at the front door to tell you that you can't come in because the store was designed for people under 6 feet tall. To see for yourself go to oldnavy.com with your 770. Of course they are paying for this, because I ended up taking my business elsewhere.
I've been working on Web applications for years. When it came to browsers, the decision to support one or the other was usually based on the resources available and the number of people who use the browser. Another browser to test could mean another set of bugs to fix; it also means setting it up (admittedly not hard) and devoting QA time to it. For something like Opera, where there isn't a huge userbase, it just isn't worth it.
Of course, I'm annoyed the browser isn't supported, too But I do see why these decisions are made.
But I do see why these decisions are made.