Web Part Connections – Improved in SharePoint 2010
In SharePoint 2010, when you put a list view web part on a page, go to the web part tool pane, and switch the Selected View in the drop-down box, the following message pops up:
The part about disabling web part connections isn’t true anymore. Back in SharePoint 2007, when you created web part connections you had to make sure that the columns being filtered were actually displayed as columns. The connection configuration only let you choose from those visible columns. You can get around this by creating these lists as data view web parts in SharePoint 2007, which allows all columns to be available for filtering.
Anyway, in SharePoint 2010 this message isn’t valid anymore because ALL COLUMNS in the list are ALWAYS available when creating web part connections. So… don’t worry about it, and click OK. That’s all.