Mike, I was hesitating to give this answer. Typically OPC will be used distributed, over an ethernet link. Did anyone test wine & native DCOM in such a way? Can you actually communicate between an application running under Wine with an application that runs under real Windows?
I'm not sure. I think it may have been used for Exchange5/Outlook connections, but you are right in that I don't know if this works.
Wines sockets support is good though, far better than its builtin DCOM. Based on what I know of the DCOM network protocol, I don't think we'd have any problems with it.
Only issue would be if you needed NT only features, as only DCOM for Windows 98 works natively on Wine.
Off the top of my head, I can't think of any big issues. Maybe dcomcfg doesn't quite work yet etc, but fixing any problems that arise would be much easier than migrating to a totally different OS, or bringing our own DCOM up to scratch ...