Heya! I'd love to point my domain (peat.org) at my blog (peat.wordpress.com), but I can't give up control of the DNS and mail for that domain.
It would be really neat if I could set up a CNAME record to alias my domain, instead of handing over complete DNS control. I think Shopify uses something similar, and it works great.
And, of course, I'd be happy to pay for that capability. :)