Muffler Rust, worry or no?

Got my 07 XC70 a month or so ago and just went underneath and noticed the rust on the muffler (I think its the muffler, someone can confirm that). Not very knowledgeable or experienced with cars and wondering if this is something I should be concerned with or not. The options I have in mind range from spraying with a rust inhibitor or replacing some exhaust parts. Any input from someone more knowledgeable is greatly appreciated. Thanks.