With the release to public beta of Popfly, Microsoft's mashup editor, I'll reiterate my theory that mashups are the UNIX shell of the Internet. The corollary is that we need a suite of command equivalents:
Command Mashup Alternative cd, mkdir, rmdir facilities for manipulating "current URI"; REST principles, etc. mailx messaging transformations and transports: mail, IM, SMS, twitter, etc. man ? jobs, ps, kill, sleep, etc. facilities for multiple mashup control ls spidering facilities / robust HTML parsing, etc. "Get-ChildItem" in all its polymorphic complexity. who FOAF finger, chfn blogging cat, sed, sort, grep, wc, tail, etc. All sorts of facilities for transformation of source to sink
Right now, everyone's concentrating on what output the mashup editors can produce or what the component manipulation looks like. I think the winner of the mashup evolution will be the one that provides the most flexible suite of components.