According to a Twitter post by Garry Illyes (Google’s Webmaster Trend Analyst), we should all expect the next Google Penguin 4.0 release to happen before the end of 2015 (ie, November or December 2015).
According to SELand we can expect the next Google Penguin Update to be a real-time version (after Google Penguin 4.0). This means that there will be no set/fixed date for the algorithm update, as it will be happening continuously. Therefore, we can expect this to be the last official/fixed date Google Penguin update. It is understood that as Google come across bad quality links on any website, it may get affected by Penguin. Conversely, as any bad links are removed from pointing to a website and/or new high quality authentic links start to point back to a website it will have an effect quickly or as soon as Google detects this.
Many website owners have been asking for this ‘real-time’ feature since 2012, as having to wait a year or so to be reconsidered has had a negative effect on many websites who were hit by Penguin and rely heavily on organic traffic.