Just in case someone wants to try it, here are links regarding the layout of the admin/write post screens in 2.5 and how to hack a few files to move the categories and tags to the right sidebar of the write post screen.
Talking about changes here...
http://www.cre8d-design.com/blog/200...25-admin-hack/
The hack files themselves...
http://trac.wordpress.org/ticket/6709
WordPress Ideas thread to add your opinion...
http://wordpress.org/extend/ideas/topic.php?id=1354
I don't find anything in the current layout aggravating enough to make me want to hack files and keep track of changes for future upgrades, so if anyone tries this please let us know how things go.
HTH