@delulo
Would the following summary about Factom be about correct? Factum lets you create ledgers that are periodically recorded in the Bitcoin blochchain. The developer only has to deal with the rules / API of the factom ledger(s) and not with Bitcoin itself.
it would be more accurate to say that they are secured by the bitcoin blockchain. Not all the data that Factom collects is recorded in the blockchain. You are mostly correct about dealing with Bitcoin rules. It depends on how much confidence your application needs. if you want to double check everything that Factom is doing, then verifying it all the way to the blockchain would give you confidence Factom is not misbehaving. This is similar to Bitcoin, where you can either run a full node, checking all the miner's work, or using a lite client on your phone. it depends on how secure you need to be.
I suspect that a majority of people will use lite clients like they do in Bitcoin. This would mean they only needed to deal with the Factom API. Initially, we are planning on having a program that runs on your computer which acts as an interface between a web services API and the Factom network. This means that we can continue to update the p2p network while the api calls your application uses stays the same.
Also the centralized handling of the Factom ledgers makes "confirmation" fast. This might be pretty wrong since I just read the wsj article. But please enlighten me if it is.
It is more federated than centralized. I believe it is like NXT, where the server responsible for packaging transactions is known before a block is created, rather than like Bitcoin, where the transaction packager is known after the fact. Since the network knows who is supposed to do the packaging, an acknowledgement from them is like having a promise from a Bitcoin miner. There is a continuum of confidence as time goes on. see#3:
https://bitcointalksearch.org/topic/m.9754449