As you know the euro has been strong against the pound. I don`t think it will get any higher personally. If anything it will get weaker due to European debts. There might not be a lot in it but if I could get a reasonable deal at the moment I probably would.
about 6 weeks before we go away we start tracking the exchange rate. last year we bought 2 weeks before we went, in the past we've bought earlier. pot luck really.