If you’re looking to contribute to core UI, you’ll want to keep an eye on Make/Core, as we’re shifting our thinking of core UI contributions to being an integral part of various areas of core rather than a separate group/workflow/etc. All of the planned features for 3.6 include UI components and participation in them is highly encouraged. Office hours are either set or being set for each team and will be held in #wordpress-dev, so as always, feel free to join discussions as they’re held, whether in IRC, on the Make/Core P2, Trac, or elsewhere. Regular updates/summaries will be posted on that P2.
Also, as you’ve probably noticed, we haven’t been having weekly UI group chats, due to a combination of the end of the 3.5 cycle and a shift in how we’re thinking about this group. For more, see @jenmylo‘s comment: https://make.wordpress.org/ui/2012/11/16/coming-soon-weekly-updates/#comment-22558. The #wordpress-ui IRC channel is always open, and we can use it for UI-focused discussions if #wordpress-dev is otherwise focused on something, but let’s all get comfortable in #wordpress-dev, too 🙂
One last thing: this shift in thinking also applies to Trac. Right now there is a “UI” component, which is a bit of a mess and ultimately not a great help for watching for tickets of interest, as UI-related items are just as often found in other components. We’re working on emptying the component out by moving things into more relevant components (Administration is a good fallback if you don’t see another) and, for the time being, adding a manual keyword of “ui-focus”. In moving things, it’s also good to just be reviewing the issue the ticket raises and testing any patches provided, marking as needs-refresh if it doesn’t apply or closing the ticket (or making it with the close keyword) if it’s no longer relevant. There are almost 3500 tickets open right at this moment, which is an unmanageable number that leads to things getting lost. Let’s help get that down while we get Trac organized. Here’s the list of tickets in the UI component, and the newer list of things tagged ui-focus. If you’re not Trac-minded, don’t worry. If you are, we’d appreciate the help!