Google isn't coming up with anything like that anytime soon. Oh and to answer the OP's question, just don't link to crap sites and you'll be fine, and don't put TOO many outgoing links (more than 5) IT
http://googlewebmastercentral.blogspot.com/2006/12/building-link-based-popularity.html The trend is going towards Link Baiting
I am selling links from quite a while, and i never saw any negative influence in in SERPS...actually when you sell links, especially site-wides, you will a little jump in Yahoo , because of the "new fresh content" i think. [ however just for a few days, i think because of the "fresh content?!" ]
In my experience having outbound links will not have any affect on your PR or your SERP's, if you are building imbounds, then you may even see an increase and you can charge more for the links you are selling.