I doubt SSL for DCC really has anything to do with filesharing. A DCC connection is a closed link so it's highly unlikely illegal filesharers would want to use extra CPU resources encrypting a connection that can't easily be traced by copyright holders anyway (I assume that's what you think they'd use it for). Even if we're talking legitimate files, if a file was private enough to be worth encrypting it's unlikely you'd be sending it out via filesharing at all.
Far more likely it'd be used to send the occasional private file (which is what DCC SEND was intended for) or that it'd be used for private DCC CHAT sessions.
