Yes, been playing some more with the clouds. I have had the last clip playing on the 360 and it not drop below 60 fps, on my laptop I get about 7fps, and yes, my laptop sux!!
So I have now put it with my dynamic sky sphere, and I think it looks pretty good. In the clip I am showing a few large clouds in a huge bounding volume against the sky sphere, then a large cloud field against the sky sphere showing the transfer from day to night and back again. I have not implemented lighting on the clouds but I think it still looks nice, the final bit of the clip is both bits together with an added mushroom cloud in the middle.
Still much to do and as ever, very little time, but I am getting there I think, all though slowly :)