Re: the shift. I'm up on some terms, down on others. But "my domain" now puts me at #1 again instead of #4. My sitelinks don't show up on that search, but they do show up on "mydomain.com."
It's hard for me to evaluate Penguin on the basis of my site. While Google does a pretty good job sending relevant traffic to most of my sites, it's always been odd with this one. This site has some great pages (IMO) that have been largely ignored by Google in favor of lesser quality sites that Google loved. The traffic Google sent me has never done much but look at the page in question and move on - they don't subscribe/bookmark, don't leave comments, only about half of them try other pages of the site, etc. So while I wish Google would recognize my higher quality pages, I don't really take issue with them finally waking up to the fact that they were ranking some of my less stellar pages way too high, LOL.
But as for the Post-Penguin SERPs in general, I'm still not loving them. Certain brands and sites like About.com seem to be ranking high whether or not they have a really good page for the query. As a user, nothing I'm seeing compels me to switch back from Bing.