One of my hosting accounts limits PHP memory, so for these blogs I need to deactivate all plugins before running the automatic update. My other hosting service has enough PHP RAM to not have to do this, which is nice.
All my blogs have now been running WordPress 3.0 in production for a few days and so far I’ve not met any problems with the core product.
One minor issue has been with the CSS minification in the W3 Total Cache plugin. I’m using the latest development version of W3TC but it has an issue with CSS so I’ve disabled minification until I’ve time to look into this further.
The new multisite feature in WordPress 3.0 seems a good option for combining a number of separate WordPress installations to cut maintenance effort. I’ve had a first look at some tutorials and it looks possible. However, not all my plugins are yet multisite aware.
So, I’ll leave my existing installations alone and give my core plugins and theme some time to catch up with WordPress core. Once they are multisite aware I’ll merge all my retired blogs into a single WordPress installation.