In reply to Mike Schinkel.

nginx does a flavor of this.

Every even numbered release (eg 1.10) is the "stable" no-new-features version; odd (eg 1.11) is the mainline (or actively developed version). Basically after a time, mainline becomes the new "stable", the version number is bumped and the cycle repeats.

If WordPress did this, say starting with version 5, every odd release would be "stable". So version 6.x be the constantly updated version and 5.x be stable. 5.x would essentially be today's 4.x unchanged.

After a year or so, 5.x would become version 7, using version 6's features and version 8 would be the actively developed version. After 8 is developed, 9 becomes stable (based on 8's feature) and 10 becomes dev.

Basically do you value a constant, shorter update cycle or upgrading only once every year? FWIW, nginx says mainline is actually more "stable" since it gets more active development time... I can see arguments to both sides. Both are production ready, it just depends on how bleeding edge you want to be and what your sites (and clients) are like.