Here you can find the tool that I have created to generate .net assembly classes for a BCS connection between SharePoint 2010 and CRM 2011. It uses snippets from the CRM 2011 SDK to connect to the generic CRM web service, and gather information about the entities. It then uses XSLT to create the classes, using the information that you provide.
Fore more information, please see my blog posts, Part 1, and Part 2.
Please use the following links to download;
To build from the source code, you will need to add refences to copies of the CRM SDK libraries (microsoft.crm.sdk.proxy.dll, microsoft.xrm.client.dll, microsoft.xrm.sdk.dll).