Given that we are now at the second official UT4 Pre Alpha build by Epic, I think having a benchmark / time demo capability would be great as it would serve a number of uses eg:
1) See what machines everyone is currently running and their performance
2) By using UT4 as the vehicle for the benchmark / timedemo / showcase there will be increased public exposure to both UE4 and UT4.
Currently if someone wants to provide an official benchmark result they have to actually have a UE4 subscription, as per this thread:
UE4 Forum - Feedback for Epic - [Official] Hardware Performance Survey
By using the Matinee Fight Scene & Elemental Demo it showcases a very polished version of what UE4 and in turn what UT4 will be capable of visually.
Cross posted here:
UT Forum - General Discussion
Linked here:
UT Forum - Trello Board
UE4 Forum - Feedback for Epic - [Official] Hardware Performance Survey