This long-standing odd/even development model was officially scrapped in 2004 thanks to the success that Linus and Andrew Morton were having working together, and significant "unstable" development began happening between each 2.6.Z release.
The OpenSUSE Project claims its 11.0 release has 207 new features. While many are fairly minor, that may only attest to the maturity of the distribution;
There is not doubt in my mind that Zypper is the most powerful package management utility available today, with many useful options and arguments that do not exist elsewhere. While its apparent complexity could be seen as discouraging at times, once you take the time to learn the tool and to understand its intricacies you will undoubtedly appreciate the effort openSUSE developers have put into creating Zypper.