I've been using IE7 for several weeks.
Can't say there are any "problems".
As I posted in the support forum, various icons come and go next to pages saved in my Favorites. The eBay icon can appear next to almost anything. The SMC icon can look like it is supposed to or morph into other strange stuff.
I don't like the new, extra, tab bar. It consumes screen space I would rathr have for viewing what I am viewing. Would like to get rid of it but haven't figured out how yet, if it is possible.