Estonia, Hungary, Latvia, Lithuania, Malta, Poland, Slovakia, Slovenia and the Czech Republic will become part of the passport-free area, joining 13 existing Schengen members, which include non-EU states Norway and Iceland. Switzerland and Liechtenstein – neither of which are in the EU – plan to join in 2008.
With the latest accessions to the Schengen area, the UK, Ireland, Bulgaria, Romania and Cyprus are the only EU member states remaining outside. Bulgaria and Romania are held in a form of economic quarantine, so one can understand their position. Both countries have signed the agreement, but will not actually implement the decision until 2011. Cyprus will join in 2009.
But the UK and Ireland?
The only credible reason why the Republic of Ireland has not joined Schengen is that its big neighbour to the east refuses to join, and the Irish are unwilling and/or unable to dismantle the (informal) common travel area between the two countries.
So that leaves just Blighty manning the watchtowers around its island fortress. Which is just plain silly, as the UK is probably the easiest European country for an economic migrant to lose himself in, and not attract the attention of the authorities.
I love these British Isles, but do not pretend to understand them.