"Of his era"?
I'd hope everyone know that Rickey takes a backseat to nobody.
I don't think they're saying Ichiro and Henderson are from the same era, just comparing Ichiro to other great leadoff hitters.  And since we're comparing:
Ichiro: 291 2B, 79 3B, 1184 R, 98 HR, 633 RBI, 439 SB, 
Henderson: 507 2B, 66 3B, 2244 R, 293 HR, 1100 RBI, 1384 SB
Ichiro was a great player, and a fine leadoff hitter.  But let's face it, he was no Rickey Henderson.  Not even in the same  league, career-wise, even.