Fair enough, but the phrasing suggests your browser isn't modern enough, rather than Grooveshark hasn't been tested to support it, which can be somewhat frustrating to a user of the browser, which may in fact be modern and up to date.
Our copy writers don't always get the why's exactly correct for this stuff, so I apologize for them for making it seem like Opera isn't modern. In reality, our current temporary lack of support for Opera is entirely Internet Explorer's fault. It took all our available resources to get the site working reliably in IE there was none left for Opera. Which sucks because Opera is /fast/ and standards compliant...but it has very few users.
