I have to agree with cmiller1014, the lack of a stable branch of Magento is a nightmare.
For example the 1.3 release broke special prices on Bundled products and its still not fixed!
These sorts of regressions make Magento a really difficult sell as every release breaks as many features as it introduces or fixes. I have posted before regarding the way Varian are pushing Magento development. New feature releases need to be slowed or separated from stabilising the existing feature set. You have to ask about what regression testing goes on before a release is made as well, some of these bugs are related to pretty front line features.
I appreciate its OpenSource and free etc. But that doesn’t mean quality has to suffer to stuff in X new features every point release. I do think Magento is a really good platform, I think it is being let down by a development process that is still placing its priority on new features over stability and QA.
Nothing would make me happier than to see no new features released for a few months, only bug fixes to existing problems.