I have a bunch of publishing sites upgraded from SharePoint 2007 to 2010 and our users have noticed an interesting difference. Not sure if it's related to our environment or a bug in 2010.
Basically when antoher user has the page checked out, in SharePoint 2007 the "Edit Page" option on Site Actions was disabled (greyed out). Our upgraded sites, running in V3 mode, so not yet run through the visual upgrade DON'T disable this button.
Once a user clicks on it, they are presented with an ASP.NET error page stating that:
This item must be checked out before its properties can be edited
The Edit Page link in 2007 production is disabled.
If anyone has come across this before and/or knows what a fix is, please let me know.