I wouldn't plan any mods until you get at LEAST past your first service and break in, but that's just my 2 cents.
That being said, I've only had mine (2012 Roadster) since november and I'm changing a bunch of things. I've only put on 6000 miles, barely enough to get used to her, but I want to feel like she's free to reach her potential.
The bike, completely stock, is delightful. I found the stock exhaust to be a bit too subtle for my taste so I put the accessory mufflers on (lots of guys talk about having TORs. Mine are JUST the offroad silencers, not the collector etc.) and it made a world of difference to the sound but didn't change performance much. It's got a nice gentle pur at idle and roars in a satisfying way when opened up.
Don't know what you rode before this, but the Rocket is definitely a big girl with a lot of spirit. It will take some getting used to and even without any mods is loaded with power.