I think this may be a bug I have logged it here http://orchard.codeplex.com/workitem/18645
1. Create a new binding to Orchard.Core.Common.Models.CommonPartRecord.Id
2. Create a new query and filter by Content Type page and the binding above greater than 0
3. Create a projection to display the above query
No records are displayed. If you remove the filter by the Id then a list of pages is shown. It doesn't seem like you can filter by any content part's id?
I need this feature to filter a projection widget by the current content Id.