That is questionable. I have well over a thousand directory links, most of them from low-PR directories. I see no penalty, and there is no reason for a penalty. PR just went up to PR5, and SERPs remain good, with about 40,000+ unique visitors a month. Where did you get the idea that legitimate directory links, in the correct, relevant category, will trigger a penalty for the submitting website?
Yes, Link Building is still very important. Without link building it is difficult or i think it is not possible to getting listing in search engines.
Link building will ALWAYS be important. However, you may need to shift the reason why you build links. Whether you buy, trade, or beg for them. The best links are the ones that send you traffic. Forget about PR, link relevancy and other Google created criteria. Look for links where someone who goes to the site you are hoping to get a link from will be interested in your site. If you do this then you will be reducing the risk of angering the Google gods also. The reason Google still counts Yahoo and DMOZ is because people still use these sites to look for other sites, very few directories are used this way, therefore Google will in time devalue the links from them (hard to say this may already be the case).
If you are prepared! Then just swing with these easy techniques. You will notice Netscape is PR 9. That is a powerful stuff and Google itself, is only PR 7. If you’re familiar with page rankings and back-links, you know what having a link from a PR 9 sites can do for your site. Just try one-way-back links to your site and in an hour I assure that your site will be in a good PR.