Google have announced that their Penguin algorithm, which penalises websites that make use of low-quality, “spammy” links has now been incorporated into their realtime web crawling and ranking algorithm.
This means that offending websites will not be caught periodically but in real time as the site is crawled by Google’s bots in the normal crawl cycle. Previously a site with poor quality spammy or unatural links, including paid-for links, could exist and be ranked quite well because Penguin did not get updated that often. Now all of that has changed and changes to your site, good or bad, will be recognised immediately during the crawl procedure and corrective action implemented soon afterwards.
Hopefully this will mean that if your website is adversely affected by poor quality links and you take steps to rectify the matter the improvement will be recognised straightaway and your ranking adjusted accordingly.
Here’s the link to the actual announcement made by Google on their official blog.