It would end up costing you a lot more I think though with the exchange rate probably best for you to wait for it to be offered on Disney US.
If it is possible(which I don't think it is) the exchange rate would work in Traci's favour. When the £ is strong its cheaper for us to buy in US, when the $ is stronger its cheaper for Americans to buy here.
I posted on Orlando Hotels forum a few days ago. A thread about Comfort Inn at $33/night(+tax), In US that is a really cheap deal but if they bought it thru a UK supplier I showed them how to get it at approx $20/night incl tax.
For Disney booking there would be a massive saving if it was possible.
compare 2 weeks at OKW this August, (based on 2 ad + 2 ch)
Disney.co.uk Total Price £2,110.00(Approx $3,230) incl free
DDP & 4 x 14 day ultimates
Disney.com Total: $6,012.06 incl free DDP & 4 x 10-Day MYW HopperS & Water Park Fun & More.
Although it would be roughly a $2,800 saving this August it wouldn't be anywhere near that for next year as OKW/SSR 42% off deal isn't available.
Last few years we have had great deals buying in US st $2/£1, Americans should really be looking at buying here just now where possible.