No problem dating this picture ... it's from 2002:
[url=http://content.answers.com/main/content/wp/en/thumb/7/7a/250px-Grey_Cup_2002_Snowbirds.jpg]http://content.answers.com/main/content ... wbirds.jpg[/url]
Not to say there weren't rounded corners in '03 and '04, but I'm betting there were.
I have no problem with "egg shaped" endzones ... it does lend a bit of character ... (and singles should only count on returnable kicks, no matter what size. 15 yards deep would be no big deal, and would make it harder on offences, but 20 is fine.)
Did Memorial Stadium really have shorter endzones? Using precise measuring (re: my finger), the close one in this pic seems to be 20 yards, at least ... and you can tell that they've avoided the rounded-off corners.
[url=http://www.oursportscentral.com/cflinamerica/memstad.jpg]http://www.oursportscentral.com/cflinam ... emstad.jpg[/url]
(looks good, hey? Awesome amount of fans. Maybe another reason why the CFL succeeded in Baltimore - the team actually tried to go along with the CFL.)