There are a lot of old themes on WordPress.com that I'd like to see retired. But I can understand that Automattic is stuck in a tough position where every single theme in their collection is going to be used and loved by many members.

One solution that I think would be a win-win would be if they retired some of these old themes, but grandfathered them in for anyone currently using them. So the old themes would lurk in the background being used on some sites, but no longer available as an option to anyone that wasn't already using them.

It'd be a bit of a headache to support those legacy themes, but at least that way no users would have any changes forced on them. And eventually they would switch on their own to the new fancy themes that Ian and the rest of the theme team are creating and those themes can just fade away quietly.

Who knows, the last few users of Banana Smoothie might really value their rare theme like an out of print Magic card :)

At the very least, it would be nice if they could bury some of these old themes in an archive so that they didn't show up as options unless you went looking for them. This is also how I'd like the plugin and theme directories to work, if the code hasn't been updated since 2008 I'm not going to trust it on any of my sites.