Garret from HipChat here - We obviously agree that lots of apps have used chat bubbles in logos over the years. In fact, probably way too many. The only reason its an issue this time around is that our users are genuinely confused when they try to use both apps. This didn't happen when they used iChat, Echofon, or any other bubble-logoed apps alongside HipChat. The new Messages icon is similar enough that it's a problem, and we don't want our users to be confused.
In fact to me it looks like the new Messages logo is derived from the old iChat logo with some of the skew removed and another bubble added. Nothing to see here...
Because (a) IRC is relatively dead (b) it sent a bunch of funny formatting codes which are a mess to read if you're not using Comic Chat too and everyone else was annoyed with that (c) it's kind of hard to find a copy these days.
Agree on the no controversy. I went looking to make a chat icon for a project about a week ago, and looked on dribbble to see some ideas before I started. Chat icons all looked the same. I found examples that looked nearly identical to the hipChat icon and did something similar in my own icon. Never heard of hipChat but the logo is not original or unthought of. I can't see a problem here.
In fact, there doesn't seem to be a whole lot of diversity when it comes to chat icons in general: http://www.google.com/search?q=chat%20icon&oe=UTF-8&...
I really don't think there's a controversy here.