Stickynotes are cute and would be easy to implement, but here is my real Genode wishlist:
Email client - I would be happy with anything
IRC client - I love communicating with IRC chat, and the folks at #genode are very helpful :)
RSS Reader - I have my most important news sent to me via RSS, and it seems most Genodians like RSS as well
Native Firefox - this is but a dream
Office Suite - I hear LibreOffice is being ported to Genode?? Cool stuff indeed
VPN - Wireguard/OpenVPN
GUI audio player
With all of this, I would be able to switch to Genode without needing to virtualize anything. I would be as happy as a clam