If the 989 really is an improvement on the 868 it's going to be a peach.
£763 for a 989 is the best price I've seen. Doesn't say when they'll be shipping tho, nor what the the delivery charge is. Ivojo also seem to have some good prices on Pioneer plasmas.
There's a seller on ebay (hifonics?) that has had several refurb 868s over the past few weeks for £549+del. Not sure this a great price, as its a refurb and you're buying off of ebay. IIRC there was a HK-based seller offering £360-ish+del for a new unit. Now that would be a bargain in the unlikely event you got lucky with HM customs....
Last time I looked, 7oaks was selling an xd 868 for £620ish. They weren't open to offers when I phoned about it. At that price, a 989 does look pretty tempting.