I'm sure you'll get a different answer from everyone. But to me it not to be taken literally, per se. It is an ideal to be strived for. Georgem, our real lead dev keeps to these principles (free markets / no-gods, no-masters). His implementation of service nodes will not be like DASH's or anything people have likely seen before.

The collateral that will be required to go into Service Nodes will be subject to market conditions. So there will be a set amount a nodes - TBD - and the "price" required for collateral will depend on how many coins other people are putting in. Georgem has done some great explanations in previous weeks and I will try to pull those up.

Ultimately the goal is to help decentralize bitcoin and support full nodes. You can skim or read the white paper here:

http://spreadcoin.info/news/wp-content/uploads/2015/10/Proof-of-Bitcoin-Node-DRAFTv1-1.pdf

I'll see if I can dig up some old Georgem posts.

Tell your friends about SPR!