Current release scheduleUbuntu releases a new version every 6 months, in April and October. They are supported for 18 months. I do not really have an issue with this frequency.
Every 2 years one of these releases is a LTS, Long Term Support, version that they will support for 3 to 5 years. This is the release to use for more production systems.
In practiceIn practice this 6 month release schedule means a lot of bleeding edge software and versions go into every version. This is good. It means the distribution is up to date, and the software is pushed and cannot rest on its laurels and falter.
Most software versions are stable enough, but however new divergences are often not polished enough and lack enough extensions, documentation, etc. E.g. Unity, Gnome 3, GDM2, Plymouth etc. For the initiated that will research solutions and like dabbling with new software this is not a big issue. For the vast majority of users that just wants something that works, this is risky and often backfires on their impression of Linux and Ubuntu.
Also a 6 months release schedule does mean quite a frequent upgrade requirement. Especially for the uninitiated non heavy Linux fanboys (if such a name exists). But you have to set the line somewhere, and a more frequent upgrade does mean a smaller delta difference and less chance of broken upgrades. On production servers however, 6 months upgrade schedule is a non starter. The LTS schedule is thus more suitable.
LTSUnfortunately the LTS version is not always the version Ubuntu "promote". After a newer minor version has been released it takes a back burner. Too much emphasis I feel on promoting, discussing and supporting the newer versions and not backporting enough to the "stable" LTS version.
Also when an LTS version is released it is "promoted" as LTS immediately. Being a "major" release a lot of people upgrade to it soon after the release date, but there are still many teething errors before it is more "solid", usually then they release a X.x.1 version.
Small modificationThey should promote LTS to everyone, and let fanboys use the latest non LTS versions. This way the keen users will still be up to date, and will ensure fixes and velocity of the features. But they will keep a very stable version for the majority users.
They should not apply the LTS "brand" to the version until the X.x.1 version a few months after the general X.x release. That way teething errors are never found in an LTS version, and more trust can be applied to the version branding.
They should include more backports to the LTS versions. After about a year my LTSes are a nuisance as their packages are too out of date.
Large modificationLTS current biennial release schedule is a large gap. What about a LTS every year or 18 months?
Have a "major", "minor", "tiny" or better "solid", "stable", "unstable" release versioning? Or an unstable release every 4 months(fanboys), stable every 8 (desktops) and solid(servers)(LTS) every 16 months? Too much admin or release confusion perhaps?
While debian's stable/testing/unstable naming is a close match, Ubuntu has always been relible. But lately I have been reluctant to upgrade, waiting months before all initial problems are out of the way before I dabble. And now I usually skip a release or two every time.
SummaryBasically change the promotion of LTS. Let the LTS be the default version. And do not call it LTS until the Ubuntu x.x.1 teething problem bugfix version is released.
And optionally change the schedule to more frequent LTS, or even 3 levels of stability/support releases.