I want to change from Kerberos to the Claim based authentication in my SharePoint 2010 environment. I want to use Access Services. Are there any technical difficulties with Access Services?
You are confusing two things.
Kerberos versus NTLM are authentication protocols. This is how the credentials are passed and verified, not the authentication itself. Claims Based Authentication can be used with either Active Directory or Forms Based Authentication (SQL, usually) users to provide a way for the user to log into the sites. I have not heard of any issues with Claims and Access Services, however, I do know that there are problems with Claims and PerformancePoint. I would suggest building this out in a test environment as a POC before changing any existing environments.