A new web part for CRM 4 integration into SharePoint has been released by Microsoft:
The List Web Part for Microsoft Dynamics CRM 4.0 provides a way to view and update Microsoft Dynamics CRM records using a Windows SharePoint Services 3.0 SP1 or Microsoft Office SharePoint Server 2007 SP1 Web site. Microsoft Dynamics CRM users can create shared or personal List Web Parts of Microsoft Dynamics CRM records from a SharePoint Web site, open records in Microsoft Dynamics CRM 4.0 from the List Web Part, and create connected List Web Parts.
Ascentium has a blog post with some screen shots.