charge off coming off report affect on score

I was working with a company to challenge things on my credit report, i am no longer with them, but I recieve letters in the mail from each of the bureaus and had a question about something with my report. It says that a charge off that i had a while ago is scheduled to come off my report in 09/11, also I had another charge off deleted from my report. what i was wondering is next year without these two charge offs on my report how much should my score go up and how long does it take for the score to go up. thank you for your help.