I'm trying to use the REST services (ListData.svc) to retrieve items from a list in a very simple test with Office365. I can't seem to get the connection to work without adding my credentials to the DataSource, which to me is a huge no-no. If I add my credentials, it works fine.

The error is the standard "Unable to display this Web Part. To troubleshoot the problem, open this Web page in a Microsoft SharePoint Foundation-compatible HTML editor such as Microsoft SharePoint Designer. If the problem persists, contact your Web server administrator.", which of course tells me nothing of use.

I admit that I haven't tried this in a local VM, but Office365 is my proving ground in this case.

I found this article on Microsoft's site, but it doesn't help me because I don't have any control over the authentication mechanisms: SharePoint Designer 2010 data sources that consume ListData.svc fail to generate a web part on sites that use NTLM authentication

Has anyone successfully used a DVWP with REST as the DataSource on Office365 without passing credentials in the clear?