Please make it possible to store Previews.lrdata at another location.
My setup is the following:
I have a NAS containing all my RAW images and I switch between several computers running lightroom. Since the catalog have to be stored on a local drive, I have it in my Dropbox, in order to sync it between all computers. BUT Lightroom also stores the Previews.lrdata next to the catalog, and I don't want this. (I know that i can use some symlink tricks but over time, dropbox messes up and overwrites the symlinks)
I consider the preview data as a simple cache, which only speeds up the browsing of images. It should not reside in the same location as my important data (NEF and lrcat files), but be located in either the temp dir or in a folder like /Users/esben/Library/Application Support/Adobe/Lightroom/Previews - Just like the way a web browser caches its files...
At least, you should make it an option to store the previews data apart from the catalog file.