I've often thought about just such a thing:
>Maybe the solution is to create a set of specification for abstract pattern
>of interactions, for example:
>Select one element from a list,
>Select several elements form a list,
>Browse and edit a tree representation,
>Browse and edit a table representation,
>Enter text,
>Enter rich format text,
>Etc...
For it to be useful, it would have to have widespread acceptance, a la exslt.org. In fact, I've talked to the EXSLT folks before, and they weren't openly hostile to the idea.
.micah