In case you read the Live Letter correctly, it seems that Eureka has a lot of similarities that are similar to what FFXI had offered (with one thing from the past).

To list the similarities:

1) Elemental weaknesses/strengths.
2) Monsters chase you across the map.
3) Fear of losing exp when getting KO'd.
4) Forcing grouping up into parties within Eureka.

Did I miss anything else? It seems to be their answer of paying back homage to FFXI in one similar way.