I was in an identical position 12 months ago and got lucky with the rate when I moved my savings over in September.
In all honesty, you're getting a good rate no matter what at the moment - purchasing-power parity would suggest an exchange rate of about 0.75.
Having said that, one look at the government/political situation in the UK does not lead me to believe that the UK is going to be a bastion of currency stability over the coming six months. A lot of that uncertainty might be priced in, in fairness, so a Tory majority could see a little rebound in sterling.
However, the question to ask is really whether Greece will act as a bigger drag on the euro than the UK deficit will on sterling. Greece is small (although potentially the thin end of the wedge) in eurozone terms, while the deficit is huge in UK terms...
With international markets, though, you really never can tell.