I have upgraded to b2 from an old version and we have been using b2 for a week, but here are one or two issues:

If I am not logged in and click on the 'Register' link (/xwiki/bin/registerXWiki/Register) it brings up the 'Login' page.  So I cannot register without logging in.  I have changed 'Always authenticate on editing' to Yes, but this should not apply to registration.

When the default editor is WYSIWYG, editing a page removes links to images.

The bread crumb (Main:Welcome Edit Menu > My Company Wiki) does not display correctly on IE7 but does on Firefox.

Thanks

Martin