(Deutschsprachige Leser kennen vielleicht schon diesen Statusbericht, in dem es auch um Bloglines geht: WWWorker - Sascha Carlin: eRONA: Wo stehen wir?)
eRONA was developed more or less at the same time as Bloglines out of my need for a decent feed reader. While working on eRONA took some month (having a real life sometimes is a nuisance), most ideas were a bit older.
Im comparision to Bloglines eRONA is targeted towards feed reading by individuals and groups as well as aggregation, hence the name: easy RSS Online News Aggregator.
And of course eRONA was written for the sole purpose to learn more about aggregation and web services, whereas Bloglines somehow needs to make money out of it.
I highly respect Mark Fletcher and his work - eRONA does not strive to be a replacement nor to rival it.