The key feature of this command appears to be the ability to send email alerts to addresses retrieved from within the search results... Splunk can do that natively since 6.1, specify e.g.
$result.to$ as the recipient for the alert emails and it'll look for the
to field in the results.
The native Splunk functionality can use data from the results as suggested but will only use the first value for the specified field name from the first result in the search.
The sendresults command takes it a step further and dynamically evaluates who to send results to, based upon the results of the search itself as well as send only relevant search results to an individual.