I've been using Yubnub (a social commandline for the web) since about 2005, and was very happy to find the bang sytax here.
Though you do have !thesaurus it would be great to also map !like which is just easier to spell.
Also !d goes to the D programming language. Seems like dictionary.com would be useful to more people.
I miss the short forms of some commands.
!urban should map to !urbandictionary
Another command would be occasionally useful is !gwp for a google site search of the full text of wikiepdia (rather than just going to an article, or using wikipedia's search.)