The WaSP Buzz writes that once the Opera web browser passes the Acid2 test on the desktop, the mobile version will pass it too.
OK, that makes sense. AFAIK they have one rendering engine that they use across platforms. If the Windows, Linux and Mac versions display sites identically (aside from fonts and form controls), there’s no reason to assume that the version for cell phones and PDAs will be any different. What’s interesting here is the link to a forum thread on Opera’s Acid2 progress.