The Wordpress plugin repository has just added a feature to try to establish a plugin's compatibility with various WP releases. See: http://wordpress.org/development/200...tibility-beta/
It's in beta and just starting to gather data, but in the near future it will be an interesting extra bit of information regarding how safe it is to upgrade to a new WP release. Those of us who strive to always upgrade immediately can help out by visiting the repository and adding our vote concerning which plugins are/are not working after an upgrade.
Now, if we could just record multiple plugin conflicts within a given WP release, wouldn't that be wonderful!
Maybe we should start a list of plugins that work standalone in a specific Atahualpa release? And document known conflicts? I'm on a quest to try a variety of gallery plugins in isolation in a virgin latest WP&Atahualpa installation -- as soon as I get some time -- please no one hold their breath.