I published a version a little while ago… it had some bug fixes and, specially, a highly improved cache mode. Thumbnails are preserved when Showcase is closed, and there’s a thumbnail sharing system between the different Showcase instances.
To be sincere, I still cannot recommend, although it’s probably the most powerful solution out there. The reason? It will take away resources. Any form of “thumbnail cache” will take away resources, and even if it’s barely noticeable, picky users will “feel” that it’s active (hint: I’m a picky user).
However, these improvements are the foundation for a “light” cache mode, that will just keep the thumbnails after Showcase is closed, and flag them invalid when they change.
I’ll start working soon on the next release, which will be 0.9.3 . It will contain a new feature: navigational buttons on thumbnails. After that, I’ll probably start working in Showcase 1.0 . I’ve some really nice ideas for it, so stay tuned!