I've just finished qualify (P2), and I've gone for a compromised set-up for the race. I really don't think you can tell how long the rain will last, in the middle of the race, and if it isn't that long the dry half hour at the end could be irrelevant. I've averaged a wet and dry set-up in the hope that I can be relatively quick in both conditions.
For strategy, I know I've gone with way too much fuel, to try and reduce pit-stops, so I'll be curious how it works. I've fuelled for the max tyre life I think I'll get, so I shouldn't have to make any fuel stops other than when the weather changes. It's all a big gamble though really, fingers crossed it works!