I wish you could divvy your Steam wish list up with tags. I also wish you could leave yourself notes about games on your wishlist.
For the tags: I'd like to remember games I think my family members would like as gifts. But, if I put those on *my* wishlist, it gets confusing.
For the notes: I'd like a line of characters to be able to say things like, "get when drops to $9" and so on.