We have released a Dynamics CRM 4.0 Titan CTP3 VPC (Virtual PC image) for any Dynamics partner to download via PartnerSource (requires login). PartnerSource is a portal available to partners who focus on Microsoft Dynamics and related business products.
If you are an ISV partner you should contact me to ask me to invite you to join Metro. Metro is the early access program we run in Developer and Platform Evangelism. It'll get you access to the bits as well as early adopter product free support and even free training.
Link for download:
Microsoft Dynamics CRM 4.0: Virtual PC Image - CTP3 Beta Release (Requires Login).