[Updated Saturday]: The San Diego Sheriff lists his release date as February 6, 2011. I'm not sure how this works out to serving 240 days. When he was arraigned this summer he was given a bond and released, which might count as 1 day. He pitched all summer for the Princeton Rays. On October 13th he was arrested and jailed after entering a guilty plea. He remained in jail until the sentencing hearing yesterday, which would be approximately 30 days. From yesterday until February 6th is less than 90 days. By my math that's 30 + ~90 = ~120 days total. I'm not sure how that is anywhere near 240 days, but that's what the Sheriff's records indicate.
Also, there has been no official comment so far from the Rays on his future with the organization.
[2nd Update]: Found the explanation for the February release date: good-time credits. It is described here, along with info on the settlement of a civil suit:
A civil lawsuit over the crash was settled, with terms not disclosed. Based on several comments made in court, it appeared the financial arrangements could depend on whether the defendant eventually scores a lucrative baseball contract.
Judge Peter Deddeh warned the defendant that if he committed even a minor traffic offense during his probation, he would be sent to prison. The judge said that because of good-time credits, Bellatti will probably be released within three months, which would give him time to participate in Tampa Bay's minor league training camp.