First I want to say congratulations to the WordPress team for another great upgrade. Went real smooth for me with only a few minor bugs and one serious one seen in the new version.
The minor one is seen in both Firefox 2.0 (the browser I use) and IE 7.0 (the browser I have to use occasionally and during testing) is the overly large fonts used in anything in the Admin that can be referred to as a "title" such as the ones in the Dashboard for the 'gray boxes, news items' or the Manage/Files titles above the editing field. If the title is longer than just a few short words then the title gets mashed together (words riding on top of another) or disappearing below the 'dialog box' (as seen in some of the the "gray boxes"). This anomaly is also seen in various parts of the Admin interface where a long sentence will run under the right hand sidebar for example (I don't remember which of the menus it was). I believe this was present in the earlier Alpha and Beta builds as well.
The other bug I've seen a more serious one and only occurs in IE 7.0 (haven't tested in IE 6.0 yet), not Firefox 2.0.
Here's and excerpt from my post about this problem from my blog:
Another anomaly occurs only in IE 7.0 in when writing or editing a post or a page and expanding or collapsing (clicking the plus or minus sign) any of the options in the right hand sidebar such as ‘Categories’ or ‘Post Password’ for example triggers the “Are you sure you want to navigate away from this page?” dialog box
This also happens when expanding or collapsing the the options below the upload manager (’Optional Excerpt’ etc) but there is another problem when expanding or collapsing these three options as well. Unless the option below the one expanded is expanded as well, the one above expands down into and behind the one below. If you expand the one below, the option field shows up the way it should. If this happens to be the ‘Optional Excerpt’ field and the ‘Trackbacks’ fields the ‘Trackbacks’ field will expand into the ‘Customs Fields’ below it until that is expanded as well.
Another problem seen also is when the above mentioned fields are all collapsed again, the 'Delete this Post' button disappears up somewhere underneath the three blue bars and only reappears when you expand the three fields again. Also, when the field are collapsed, there is a large gap between 'Optional Excerpts' and 'Trackbacks' where the 'Optional Excerpts' field used to be.
Again, this occurs only in IE 7.0 and Not Firefox 2.0
More info on this can be found at my blog (just check my profile for the URL since the URL for the post is too long to put here and I hate to be rude).
I hope this info helps some and please forgive the long post and any problems with grammar. I tend to get a bit wordy at times. Heck, I'm wordy all the time, who am I kidding :-).
Thanks for a great upgrade.