Just updated the shared Plone instances on on Inigo to 2.5.4. For users,  there will be noticeable performance improvements, mostly in uploading content.

While Plone is very easy for users with lots and lots of features in each major version, the rapid pace makes tracking it for developers keeps you on your toes. Current stable version is 3.0 and previous stable version is 2.5, but 3.1 and 3.5 and 4.0 branches are already available.

This access to future development versions, is one of the major advantages for FOSS developers. Not only can you do testing at very early stages (agile development), but you also have insight into new features that are available in the next version. In one project based on proprietary products I'm aware off the release was so slow (3 years) that by the time development to add features in in original version was finished, they found out that in the new version, the vendor already incorporated these development as new features. That would suck, because definitely the clients would ask, what exactly did way pay for before, and why do we need to pay again for new licenses for those same features? And why do we also need to upgrade and pay for even more licenses every other dependent software in our infrastructure too because of this major upgrade? And why are the previously developed products so unstable on this new version?

With good engineering practices and early access to everything including input on key features that may effect you, this is one place where FOSS development method is clearly better for large  long term projects.

Will ZFS be in FreeBSD 7, you know it will, you have access to the CVS source and can see that it was committed in. You won't suddenly be shocked that it will be removed. If you  really need it you can even provide resources for additional development. You also know that USB storage isn't something you want to be dependent on unless you're willing to fund more developers to work on it. You can then plan ahead, and buy dual usb/firewire devices for backups on your FreeBSD servers.