This is a light version of the Ubuntu software center?Optimized for Lubuntu?It would replace synaptic?
Yes :) It's in a very alpha stage, but it works. In the future this will replace Synaptic, because of this one is not very user-friendly. Ubuntu 11.10 has removed Synaptic too. It's "optimized" for Lubuntu because it's designed specially for Lubuntu, but any Ubuntu user can install it.
It is not a Ubuntu Software Centeroptimized for Lubuntu, because Stephen didn't used the USC code. He build this almost from scratch. But obviously the idea was based on USC.
I like it. :)