I've just had a look at the daily data in which our weather station recorded frosts this year.
So far in 2011, of the 16,272 half-hourly temperature readings recorded, only 46 of them have been at or below 0°C. That breaks down to 2 hours' frost in January (30th/31st), 7.5 in Feb (all on 1st Feb) and 13.5 hours in March, over 4 days (5th, 7th, 8th, 19th). I'm confident that the recordings are accurate: we almost invariably follow within a degree or so the met office reading from Landwick, (Wakering/Shoeburyness) with the exception of hot days. The more exposed, coastal and rural setting of the official site I'm sure keeps its temperatures down. I suspect that very cold winter weather might also give variance, but we haven't had any yet.
Unless what's left of this month throws something dramatic at us, I expect 2011 to be the most frost-free year ever recorded in SE England.