Not just .bit or .onion domains, but a plethora of ‘new’ / ‘alternative’ TLD’s, generally inaccessible via the clearnet could be supported i.e.
Emercoin - .emc, .coin, .lib, .bazar - http://emercoin.com/EMCDNS_and_NVS
Namecoin - .bit
New Nations - .uu, .ti, .te, .ku
Open NIC - .bbs, .dyn, .free, .fur, .geek, .gopher, .indy, .ing, .micro, .neo, .null, .oss, .oz, .parody