I'm a huge fan of the option to create a nice looking online album and share that with clients. I'm also getting very positive feedback about this way of sharing photos instead of sending a .zip file. Clients can just choose the photos they want to use and only download those.
The only function I'm missing right now is the possibility to define the name of the downloaded jpegs from a shared album. Usually when I share the .zip file I change the file names, add the date of the shoot, the subject and my name. I often shoot festivals and events, where the team changes regularly. So having my name in the file name is very important to get proper credits when the photo is used.
Since we can't change the file names within Lightroom and I saw that idea was declined, I hope it will be at least possible to get an option to define what the file name should be when someone downloads the .jpeg from an online album.