I'm not anti ripple, but can some one explain how the UNL is not centralized.
Essentially unless you make it onto the UNL list, the ripple running servers don't include you.
How do you get on the UNL, well the others or majority of existing servers have to decide to add you.
Unique Node List = UNL
The UNL is not unique to the entire Ripple network. Each validator gets to choose which other nodes are placed in its own UNL. That is, each node operator chooses who to trust.
The "unique" terminology comes from the idea that the validators that you place in your UNL should be unique entities, so that you don't fill it up with nodes controlled by a single agent who might have his nodes collude against you.
It is fine that you don't trust the nodes in your UNL as long as you trust that they won't collude against you. You might not trust either the Road Runner or Wile E Coyote, but you can trust that they won't collude against you, so it would be OK to add both.
See thethe Ripple Consensus white paper for a more formal description:
https://ripple.com/files/ripple_consensus_whitepaper.pdfbut what if the majority of existing UNL dont wish to include you can not just opt in like BTC/POW or Peercoin/POS as I understand.