I'd say that this is generally possible, since the DNS protocol is still the same.
But I didn't check the DNS-resolver yet, neither I have experiences with SEC-DNS yet. But I'll try to post an update on that as soon I found some time.

IMHO, on the other hand: If there is a namecoin blockchain on your machine or in your network running DNS-SEC is not necessary since the requests go directly to the local blockchain.