In Scott Guthrie's latest blog post, in answering the comments, he did say that Opera is slated for future support in Silverlight 2.
">>>>>> Any news on opera and safari windows support? I'm a diehard opera user and can't view any silverlight apps yet. This also stops me from using silverlight yet, although I like it like 1000 times more than flash.
We are planning to support Opera and Safari on Windows in the future (they kinda work now - but we haven't done a full test pass on them for beta1). It is definitely something we are looking to-do in the future though."
Pete