The Internet Movie Database has updated their page recently for Liberty City Stories. So far it only lists 1 one of the actors doing a voice. That is of course Frank Vincent who is the voice of Salvatore Leone. Also on the page is a little plot summary for the game:

The year is 1998 and Toni Cipriani has been laying low for a while now. Salvatore Leone requires his services and takes him under his wings, Toni must work his way to the top to become Capo. However, gangsters and other Families stand in his path to the top.

Also, Take-Two released a press release yesterday saying that the 3rd quarter results will now be discussed on September 7, 2005. Not only do they discuss their financial results, but also current and upcoming games by the company. There is a good chance that they will be talking about Liberty City Stories (maybe a release date) and I will keep you informed if anything "interesting" comes from that.

A huge thanks to saintdave for the heads up