Improvements to panels are going steadily. I have worked out the issues with coordinate calculations on both Windows and Mac. This means that panels with titlebars appear and work properly. I also think I’ve almost worked out how popup activation and focusing should work. More details of what steps need to be done are on the Panel Improvements page.
I also have been investigating better support for the arrow style popups. These display an arrow that points to an element which can be used to get further information or perform actions related to the popup. I’m working on making the arrow properly position itself even when the popup itself is pushed around to fit on screen. See bug 554937 for this feature, and bug 558072 for some preliminary work.
Bug 379745 adds support for templates and to the sort service for setting three special sort hints. The first allows one to sort by integers instead of strings, overriding the type of the data. The second allows case sensitive sorting, which probably isn’t as useful except for file listings on some systems. The third allows only sorting in ascending or descending order, and not having the natural sort state. This is accomplished via attributes placed on the root element, or the <treecol> element.
Also, I investigated some minor focus issues and resizer rendering problems. For instance, in bug 554635, it was discovered that <object> elements default to not being focusable.