Here is my proposal for a Linux distro release cycle

• major releases every 2 years
• point releases (accumulating updates) every year

• releases happenning on the beginning of the year, ideally on the 1st of January
• versions based on calendar years - version 10 released in January 2010, version 12 in January 2012, etc.
• upgrades supported only between point releases, major releases would require a reinstall
• 3 supported releases (generations) at any given time
  • 2010 - 10.0, 8.2, 6.4
  • 2011 - 10.1, 8.3, 6.5
  • 2012 - 12.0, 10.2, 8.4
  • 2013 - 12.1, 10.3, 8.5
  • 2014 - 14.0, 12.2, 10.4
  • 2015 - 14.1, 12.3, 10.5

This way one would know what releases are out there, how long they have been around, how log they will be supported, and when to expect a new one.

(I wish Debian adopted this 3G release cycle)