I remember this site from a Netted email. Looks promising but I believe it will be hard to convince people to switch from Delicious. Good luck though..
I think Delicious is popular for its Firefox add-on which gives you all the functionality you have on the site. Thats why the first thing AVOS guys did was implementing an add-on for Firefox 4 which was something everybody was dying for. I think you guys also need such an add on instead of something just lets you bookmark. Other than that the design and the simplicity of your app looks good enough for me. Keep up the good work.
You are quite right about the delicious add on. We started working on some improvements to our Chrome and Firefox extensions which will hopefully make them have the key functionality of the site itself.