They have come from a 1% Fed rate to 5%
http://bigpicture.typepad.com/comments/2006/05/real_estate_dat.html
although I don't believe the ARM has moved by as much (1 year Freddie Mac link below)
http://www.freddiemac.com/pmms/pmmsarm.htm
FED predictions can be found here
http://clevelandfed.org/research/policy/fedfunds/Index.cfm
I personally think the U.K would've continued to drop if we hadn't had the 0.25% cut last year
http://www.houseweb.co.uk/house/market/irfig.html
With at least one 0.25% interest rate rise currently predicted for the U.K. over the next year it will be interesting to see what effect this has on the U.K. market.