One of the big annoyances I run into during WSN installations is cookie conflicts. If you only have one installation per domain you never have to worry about this, but I've often got dozens. There's nothing more frustrating than running the setup and then not being able to login to the admin panel because some other installation used the same cookie names from who knows what path, perhaps a global cookie from some other subdomain even. Digging through Chrome settings to remove the cookie to get in to change the cookie names is no fun.
The changes I made a couple weeks ago to the $leaveencoded and $nomemberinfo flags have had more than their share of hard to notice side effects. The latest I've found are the menu manager delete buttons not showing and the manage redirects page acting as if all switches were off when they're not. Hopefully I've caught all the recently-messed-up admin pages now. There was also a problem with the category level selector for the add url list option, caused by having more than one level selector on the same page... I thought I'd fixed it before but apparently not fully until now.
Due mainly to 16 years of legacy, WSN uses tables as the default way to arrange your category and listings layouts. This has the advantage of making it easy to control the number of columns per row (via the settings at Admin -> Settings -> General), but the disadvantages of being considered poor practice and not reflowing easily on mobile devices. To address the mobile problem, a year or two ago I added mobile override options on the mobile settings page.
Someone today found the indent -s in the category level selectors confusingly unexpected. On consideration, the indent only makes sense for non-level selectors. Thus I've added a separate option for level selector option html compared to non-level selector option html, and have removed {CATINDENT} from the level selector one. I've also removed the category selector denied permission option html setting, which was using optgroups for MSIE7 support... it makes more sense these days to simply automatically apply the disabled attribute to the options since all browsers since MSIE8 support it.
Today, I've been working mostly on updating the WSN KB blog theme. That's the theme this blog is based on. The main change I wanted to make was to add a simple subscription button. It's much better for a blog to have a button to click on the front page for members to subscribe to email notifications of all new blog entries, instead of expecting people to edit their profile and set 'Notify of all new blogs' to 'yes'. To do this I had to change the backend to make it possible to subscribe with a click.