I'm pretty satisfied with what I have at the moment, as I currently have all the ones I use with any frequency. However, in my dream world I'd be able to have them all available, rather than saved on an external drive on my home computer to upload later. Then I'd be able to pick at the time of posting, rather than thinking "Oh, I wish I had an icon for this" and just using my default instead. And I have well over 1,000 at home.

Edit: That would also mean that I'd probably need a better bulk uploader, or a way to copy the credit details and icon from someone else along with a way to download, backup and then later reimport all my icons along with their credit and description details.