ArenaNet just announced yesterday that a few hundred accounts were banned for utilizing some of the exploits in the game to the extreme. I would venture to guess that many of these people went so far as to only use the exploit when playing the game rather than doing anything else. They likely did this is an attempt to gain massive amounts of gold or make the game incredibly easy and some other facet.
I would advise against utilizing any exploits that you find. The game right now is going to be a little bit more difficult for everyone just because we don't have a whole lot of gold to work with. It is important to remember that not only do you not have a whole lot of gold, but neither does anyone else. For the last week the trading post is been down and almost no one has been able to make a whole lot of gold. So I can understand why it is so tempting for someone to utilize a bug in the game to make easy gold at this stage.
There is no absolute guarantee that if you use and exploit you will be banned from the game, but we now know that ArenaNet are actively watching for it and will take measures against you if you are found to be abusing it.
Instead of finding and exploit and using it over and over again I would suggest that you file a ticket with ArenaNet and let them know about it instead. Not only are you helping the game, but you are also helping yourself stay competitive as well. If other people find and exploit they may keep it to themselves and abuse it for personal gain. There is the chance that they will be banned for doing so, but there will always be those who fly under the radar and get away with it. If you take the initiative to let ArenaNet know about it the bug will be fixed and you ensure that you and everyone else are on a level playing field. You haven't use the bug – therefore you're not risking your account being banned. The competition will not have the bug to use to their advantage either if it is fixed in a timely manner. The best thing of all is that the game just gets that much better.
Finding exploits in a new MMO is incredibly tempting to use for your own personal gain. I am the same as all of you in the sense that I'm trying to find ways to make gold more efficiently than my competition, but I still want to do it the right way. If making a few gold off of and exploit leads to a chance of my account being banned there is just no way that I can tell myself it is worth doing.
So – if you find a bug in the game make it your mission to let ArenaNet know about it so they can get it fixed quickly. Major blogs like repeating nodes can have a real damage on the economy of the game especially with bots already existing for Guild Wars 2.