Why shouldn't they? Chrome/Chromium for example have full (and pretty good, much better than Mozilla, on par with IE) support for Estonian ID cards (smartcards/PKI) - why shouldn't Opera do the same? I could understand that adding required infrastructure to Presto would be task too big, but as Chromium already includes that support, I can't see that big obstacles implementing it in Opera also.
I recently started to domesticate newer Operas - but what point this has, if I lose many of Opera 10/11/12 features (even using couple of extensions) and do not gain even IDcard support? How can I even recommend Opera to any fellow estonians, if it doesn't support ID card?
Or maybe smartcards do work in Opera and I have just something missing in my setup?