Need for it to work with Opera too!
Edit: a few more things that might be an idea to implement:
1) in regular irc you have a feature that when you write a letter and then hit the tab-button you browse through the nicknames on the channel, so you dont have to write the whole nick, making the /msg (beeing case sensetive and all) much more easy.
2) the /msg function without opening a new window: you should also have the messages you write to a person shown in "whisper"-mode on the all-chat room, like it is when you recive from people. Then you can see that the message is sent from your part
I prefer /msg instead of opening windows since it saves space, but it needs a bit of boost