When you start the new launcher without an internet connection, the left panel (update news) just says "Loading update news.." (also note the missing third dot) forever. This implies that minecraft re-tries again and again to load the update news, never giving up. However, that is not the case: When I plugged my network cable back in, nothing changed. At time of writing, Minecraft hasn't managed to recognize the internet connection for five minutes.

I think a better behavior would be to change the message to "Unable to load update news" if it fails, instead of just leaving the message.