It's unfortunate that Ubuntu's Mark Shuttleworth doesn't blog more often, because when he does, it's invariably insightful. As a case in point, Mark's post about the superiority of open source at hitting release dates is wonderful. He writes:
Most people would assume that precise release management would depend on having total control of all the moving parts - and hence only be possible in a proprietary setting. Microsoft writes (almost) every line of code in Windows, so you would think they would be able to set, and hit, a precise target date for delivery.
But in fact the reverse is true - free software distributions or OSV's can provide much better assurances with regard to delivery dates than proprietary OSV's, because we can focus on the critical role of component selection, integration, testing, patch management and distribution rather than the pieces which upstream projects are better able to handle - core component feature development.
Unfortunately, it may not be true. At least, not the extent that I'd wish it.
As many have reported, including in the comments to Mark's post and including hard-core Ubuntu fans, Ubuntu's 8.04 release that Mark lauds still has a fair number of bugs that might have been resolved by more testing (read: time) put into the release...before it was released.
Ultimately, a solid release - be it of open-source or proprietary software - depends on excellent product management, and that really has nothing to do with source code, and everything to do with people. It is true that open source tends to be more regulated by product readiness and feature completeness, but the more commercial open source becomes, the more it is subject to the same market demands that proprietary software is: A product ships by X date, whatever the cost.
I wish it were otherwise, but I've yet to see an open-source company escape market requirements.