I might be wrong, but AFAIK the package info comes from the local package
database (which doesn't store where the package came from) and the channels
information (that doesn't know if they're installed or not). There is no third
information source, which means it would be rather difficult to implement such
feature, unless this third db could be implemented. There are many implications
on that, including speed (cache/db update, search, etc), and data accuracy (two
dbs aread easier to sync than three). Perhaps Niemeyer should give the final
word here, as being the lead (only?) developer, but IMHO this can't be
implemented without a big review and many changes in Smart.