I just hope he doesn't mope around thinking about Sirius for too long.  Presumably, they will still use 12 Grimauld PLace for headquarters, so when Harry arrives there during the summer (I'm assuming he will at some point) he will just be reminded about Sirius all the time.
We need more Potter-Snape interaction before returning to Hogwarts.  I want Harry to try hex him without the threat of detention/expulsion.
			
		
  You know, there's only a window of 1 month's time that Harry could hex Snape without that threat, right?  This summer, he's still underage.  Next summer, after his seventeenth birthday, he'd have one month before going back to school that, I guess, technically he wouldn't have that threat... or is there always the threat of expulsion for students who hex teachers, even on holidays?