Welcome to the effects of the global meltdown! Isn't the current split between the UK MSRP and the street price about 700 quid? If so, it seems like it's probably going to start out in that range.
The Canon MSRP never matches the actually street price. The current lens has a MSRP of £2,300 and sells for £1,500. The only time the MSRP is current is the initial batch, designed to extract as much money as possible from those impatient people with deep pockets or Beta testers as I call them.