I did a test upgrade this morning and everything went so smoothly that I decided to just bite the bullet and switch over to the test site! The only thing that didn't make it over was the Video pages. That's because they use a CCK field format that's not supported in Drupal 7. No big deal, because Youtube linking is supported in the new Media Gallery.
The new system works by allowing users to create their own galleries. That was the original intent of Holdergals, with the "Small Contributions" album intended for people who just wanted to add one or two images without me having to create an album for them. With the new system, your album (called a "gallery" here) is creating automatically when you upload an image. Less work on both our ends.
Anyway, everything besides the video pages made it over, so kick the tires and let me know if you find any issues.
I'll be adding the original Gallery2 gallery later, then start migrating the images over to new Media Galleries here.
Share & Enjoy,
Eric