Same issue here – The sidebar is VERY slow, and does not load well.
Personally, I think this was not the best move (redesigning the sidebar). While ease of use was taken into account, things such as flyouts, etc. use more resources (therefore while the idea was great, the implementation and result, contributed to an overall decrease in the performance of WordPress).
This has me concerned, as this is the first time ever, that clients have asked me to move them off the WordPress platform. (And I’ve been using WordPress in one manner or another since it was first launched).
I’m equally concerned as the new version 3.3 appears to have a serious negative performance impact (on site and admin speed/response); in particular as I’ve seen numerous (and increasing) complaints about online, this over the last few hours.
What can we do to fix the performance?