The ruling:
http://www.itv-f1.com/news_article.aspx?id=43853
"The stewards, having received a report from the race director and having met with the drivers and team managers involved, have...determine a breach of the regulations has been committed by the competitor and impose the penalty referred to," said an FIA statement.
Hamilton was deemed to have "cut the chicane and gained an advantage", thereby breaching Article 30.3(a) of the sporting regulations and Appendix L chapter 4 Article 2 (g) of the International Sporting Code.
What will be appealed:
http://www.itv-f1.com/news_article.aspx?id=43860
"Although the British driver let Raikkonen back through to the lead of the race after rejoining the track, it is understood the stewards felt he had still benefited from going off-track as he repassed the Finn almost immediately at the La Source hairpin."
It could be argued that Lewis would have passed Kimi anyway, that Lewis is better in the wet than Kimi, all sorts of "could have" arguments can be dreamed up, but these arguments are pointless because they didn't occur. What did occur is that Lewis passed Kimi at La Source and a plausable reason is that he gained advantage when he cut the chicane. Lewis was very close to Kimi at the line, a position you would not expect him to be had he followed Kimi through the chicane.
The position of the stewards is presented above and it seems to me the appeal will have to show that Lewis would have passed Kimi at La Source anyway, I think it will be difficult to show that.
The whole incident is most unfortunate as everyone has an opinion, often clouded by their own person wishes and prejudices. It's unfortunate that Lewis didn't give Kimi La Source then attacked.
On a different subject I was amazed that Ferrari didn't pit Massa for inters with 2 laps to go. Conditions were rapidly getting worse and it could have moved Massa up. Heidfield pitted for inters with 2 laps to go and came 3rd. He did benefit from Kimi crashing out but at the end the inters were good for 30 seconds a lap.