DMS is a great plugin but I think it lacks a feature that would increase its usefulness exponentially and make it explode in popular use.
Currently, we have the ability to map a domain to a page or individual custom post type post. DMS could take that a huge step further by allowing domain mapping to a CPT archive.
Using the DMS example as a explanatory jumping off point: Say mycompany.com has a CPT of "Products" (mycompany.com/products) with two popular products mapped to their own domain (myregularproduct.com & myspecialproduct.com), but in addition to (or instead of) mapping a domain to an individual page or custom post type, you could also map the "Products" CPT archive to mycompanyproducts.com (e.g. mycompany.com/products --> mycompanyproducts.com).
Does that make sense?
Personally, I'm not looking to map a domain to a specific page or CPT post, but to an entire CPT archive. This feature request could do for single blog installations of WordPress what the MU Domain Mapping plugin did for multisite network installations.