Careful, the blue card won't let you move around Europe as a citizen. They're issued by individual countries, so you'll have residency rights in that country, but standard "90 in 180" freedom of movement within Schengen beyond that:
> If you hold a residence permit or a long-stay visa issued by a Schengen area country, you will have the same freedom of travel as a Schengen short-stay visa holder.
> If you hold a residence permit or a long-stay visa issued by a Schengen area country, you will have the same freedom of travel as a Schengen short-stay visa holder.
https://web.archive.org/web/20180108183307/http://ec.europa.... (the main website is down, but here's a wayback snapshot)