First off, as a long time WP user, I want to say I am very pleased so far with 2.5. Being a full time photographer, I was inclined to upgrade for the multiple image upload feature. However, I feel that this feature, like all new features, is young and incomplete. While technically it's exactly as advertised (you can upload multiple files at once), it's actually likely to be more work than the old version of WP if you are uploading many images and adding titles to each image. Here's what I think should happen:
Step 1: Upload the images
---they crunch, GOOD!
Step 2: Click on each separate image to modify individual details (as you can do now)
---Modify the "Apply to All" settings to create/change settings on all images in gallery at once
Step 3: Send all images from gallery to post (formatted in the post exactly as they would be should you add them individually.)
That's it. Currently you have to modify each and every image one at a time, and then place them in the post one at a time. This is a huge problem if you are adding 30-50 images per post at a time as I am, especially as the post grows longer with each image insertion. We have bulk upload, now let's get a real "BULK ADD" feature.
Hopefully this all makes sense.