No news is good news! I applied the WordPress Upgrade 3.4 from 3.3.2 and so far I haven’t found any conflicts with my themes of plugins on this site. And I use a lot of plugins (currently using 29) since I use this as a test bed to explore plugins and themes. I don’t recommend this many for my clients’ production sites. No problems are good news.
Now I start upgrading my clients’ sites (after appropriate backup of course). I do recommend BackWPup to grab the wp-content files and database