1:49.42 (56.77 - 52.65) last 800m for Waskom in a 3:39 race. Very impressive, but it's also worth noting that Nuguse and Hocker closed in 1:48 (also 56/52 iirc) to run 3:35 in this race three years ago. For that reason I don't think this performance alone should give Nuguse/Hocker/Kessler much cause for concern.
That said, Andy Powell surely intends for Waskom to be significantly fresher for the Trials than this race so I think he should still be considered a genuine threat to make the team if one of the favorites falters. Before regionals Waskom generally hadn't run well since last summer (excepting a 3:53 mile in the winter) despite racing full indoor and outdoor seasons, so I figure Powell is planning a particularly dramatic taper after a very hard year of training intended to ready him to make the team.