Actually...
For the Olympics, Britain does select individuals to form a squad and creates a team from these players. There are many mixed views in Scotland just now about whether this squad based drive for Olympic success is spoiling competitive curling. I think forming your own team and having playdowns, as in most countries, is the fairest way to select the team for the Olympics.
It just so happens that the GB Murdoch rink selected for Torino have largely stayed together, with good international success (as Kevin Martin knows ), and have been selected again for Vancouver. It's a pity they don't seem to be playing so well this season (yet).
The GB Womens team has been brought together from different rinks resulting in a reduced entry for the Scottish Championships this year. They seem to have gelled quickly though and have had good results so far this season. I still don't like the squad system though!